This helped me a lot when I was first starting...

https://forums.galciv2.com/104908

The answer is that most often the best thing you can build on a new colony is nothing. Wait a bit with the approval set to 100% and let the planets population grow before you start putting buildings on a new colony. Don't be in such a rush to build factories that you won't be able to afford to use for quite some time. The support for your initial colony building is fairly large, wait until the planet can at least support the maintenance of that before you start adding the support costs of other buildings too.

Here's how an invasion normally proceeds. I've never heard of an invasion "freezing" in the middle although I suppose it could happen. It may just be that you simply lost the battle.

The first thing that happens in a invasion is the selection of tactics as shown in the following screenshot.

The first thing to note are the attacking and defending race statistics shown in the top left and right of the screen. This shows the number of troops each side has along with their "Advantage" which as far as I know is merely each races relative Soldering ability.

To figure your chances of winning the battle simply multiply your number of troops by your advantage and divide that by their number of troops multiplied by their advantage. In my case that's 1250*7/6000*4=36.5%.

Since a value of 50% would indicate that I had an even chance of winning the battle it's clear I need to do something to either increase my advantage or decrease my opponets advantage. That's what the invasion tactics are all about.

If I were to simply attack with Traditional Warfare I'd be pretty certain to lose. The battle might start out with my opponent losing troops at a faster rate than I because I do have an almost 2 to 1 Soldering advantage however there's no real doubt that I would lose.

So in this case I happen to choose Mini-Soldiers that gives me a 40% to 70% gain to my advantage factor. This changes the calculation in the worst case to 1250*7*1.4/6000*4=51% and in the best case to 1250*7*1.7/6000*4=62%. I like these odds a lot better than the original 36.5%.

There's actually another whole discussion you can have about invasion tactics. You need to be a bit careful about tactics that actually damage the PQ of the planet but Mini-Soldiers at worst destroy a building or two that in most cases can simply be rebuilt so they're pretty safe. Another thing people do that can be a more efficient utilization of their troops is to is to use a damaging tactic like Core Detonation or Mass Drivers but use fewer troops so that the first invasion will fail, but even though it fails the first invasion reduces the defending troops down to a more manageable level so that a 2nd transport can use less damaging tactics and overall you'll lose less troops. But this is best left to another discussion.

So anyway at this point you've selected your invasion tactics all you can do is to "Cancel" or "Invade". If you select Invade you might first have to get approval from the Senate first but if that passes there's nothing you can do you're basically committed to the invasion and you get to the following screen.

Before you hit the "Attack" button you'll see you and your opponents advantages ranging between their min and max values. At the point you hit the "Attack" button the exact advantage is selected and that's what's used to determine the battle. At this point the battle animation proceeds and the "Attack" button turns into a "Skip" button which allows you to skip the animation. Once you skip the animation or the battle ends then the button turns into a "Done" button and all you can do is to exit the screen. The end of the battle is indicated by one side or the other having 0 troops left and the other side doing a little dance.

The thing is if the battle does "freeze" then the battle would stop with both sides still having non zero troops left and as far as I know there is no button "Close" or otherwise that you could use to exit. Like I said it sounds like you simply lost the battle.

It's worth noting that a Starport can be rushed for as little as 142 bc.  In the initial frenzy of colonisation, you can't just have one planet pumping out colony ships, so the sooner you have the Starport running the more turns it will spend building colony ships.

The initial colony itself has enough manufacturing and research facilities to start off with, but as you start to build more expensive ships and research more advanced technology, you need devote tiles to factories or labs.

Snagging every planet going will cost you in terms of just maintaining the initial colony.  Also, sending off colony ships from planets which are themselves new colonies will mean it takes longer for the population to grow to the point where the initial colony's cost is actually covered.  So you should always consider just how many worlds you need and let the other empires bear the cost of developing some new and difficult colonies.  Do you really want turns and turns of Soil Enrichment on your Social budget?  I thought not.

As a rule of thumb, you should start building some more economy buildings when the population is just over 1B.  By the time they're finished, the population should have grown enough that you'll get a net return by having those buildings on the planet (usually they incur maintenance costs).

If you need to save money during the post-colonisation phase, you can stop building ships at some of your colonies.  When money is available to build things at a colony but there is nothing being built, no money is actually spent from the budget.  This is not necessarily reflected on the colony screen, but it is reflected in your budget.  Doing this means that if you really do still need to build some ships, the colonies which you need them built at will get funding enough to roll them off the production line in a decent time.

Try to avoid having the production slider (the one under the tax slider) all the way to the left since it effectively means all your factories and labs are running at very low efficiency, giving comparatively few manufacturing or tech points for each bc of maintenance incurred.  If you can run at a deficit (spending is greater than income) for twenty turns until your population grows enough to close the gap, keep the production slider as far to the right as possible.  If you can't, consider demolishing buildings to reduce your maintenance costs.