Hello people!

The early access started and as I expected I have too many questions right off the bat about progress and numbers in the game.

First: When is the best time to colonize a Planet and in which frequences should I colonize other systems?
Second: If I'm able to colonize a planet, what are 'good' stats to determine a good spot to colonize? I know, that things can depend on the faction I play, but it would help big time if I had any kind of orientation! :D

Thanks in advance!

Longer answer: What you're asking for is a build and tech order, and, honestly, it's extremely difficult to provide one that works for every single situation. 4X games are all about being adaptive in attempting to answer the question of "What do I do now?" while you have imperfect information. Being correct 100% of the time is just not possible because you'll almost always find something the next turn that makes you say "Well dang, if only I had known..."

Probably the best advice I can give you, and this is true of most 4X games, is to focus on building up and expanding as much as possible while keeping an eye on threats. In Endless Space 2, this could be starting next to an aggressive race (read: Cravers or the Vodyani), or maybe colonizing too quickly so that you run into the over-colonization penalties, or just having your colonies getting wrecked by space pirates. Out of all the FIDSI, Industry's the one that unequivocally powers the engine of growth. With strong Industry, you can shore up the shortcomings of your colonies through the great number of improvements you can build in the game. Of course, you need Science to get the techs to unlock these buildings in the first place, but once you get them (and you can get them quite quickly early on in the game), you can turn any colony into a powerhouse of whatever the heck you want it to be.

Techs are tricky since they follow Endless Legends open system of picking whatever the heck you want. Again, there's no one right answer, although there are actually some wrong answers: Picking up N-Way Fusion for the Impervious Bunker seems like a huge mistake unless you're absolutely confident that you're going to be invaded within the first couple of turns of the game, or are planning to go to war right away... in which case you might as well restart the game!; Inter-species HR seems quite meh unless you want the extra influence for a powerful early-game law or for the border expansion to help capture a nearby bonus system. Also, getting the Titanium and Hyperium techs without a source of income of those resources (or getting a generous helping of those goods from exploring) is probably wrong. What is probably right is getting stuff that boosts your Science, Industry, and maybe even Food. Getting the Rare Earth Foams tech is great if you're stuck in a small constellation at the start of the game, but can be quite useless if you find yourself in a large constellation and if you find no Tropical planets to colonize. Getting the Xenology/Plasma Metallurgy to turn on your home system's Titanium and Hyperium production can be a great idea. More Science via Non-Baryonic Particles, More Industry via the aforementioned Xenology/Plasma Metallurgy is great.

Some races change this on its head. The Lumeris don't care about Colony Ships, so you can just go crazy with the dust-making and insta-settle colonies instead. The Sophons and Cravers need to do it traditionally and so need a strong Industry base to do so (Cravers'll certainly need more attack ships to hunt after Minor Races), and the Vodyani want a strong Industry base to build the necessary attack ships to properly leech their way to more Arks and Population!).

So, summary. Colonize as much as you can until you can't colonize no more. Sit down and figure out if building the Drone Networks early on for the +5 extra Production is worth it (the answer is usually yes), or if it's better to grab a Colony Ship.  Get more Industry. Get more Science.