Ah....ouch? Either I did something massively wrong by accepting the suggested starter galaxy and following the tutorial (which was way slower than it should have been; found myself ahead of it in little time), or this is a pretty tricky game
I don't recall ever losing a game on the easiest settings since there were such things as difficulty settings. Civ 5? Hadn't played it since a little of 2. Overwhelmed the AIs on the easiest setting without bothering to even check the controls. Etc. I am pretty sure that I took way too long to start doing the right things.
I had a good sized area under control, about comparable to other races. I had no problem dealing with any threat except this one time early on in the game when one group of marauders that showed up with about 9k of power when my total fleet was around 1k. So I paid them a little excess energy and they buggered off. Eventually the other horde united instead of infighting. I thought everything was going fine anyway. But eventually they started taking over systems of other races a ways away, so I started building up my fleets. Didn't matter. By the time I had about 10-12k in estimated power built up, even concentrated in one system they were heading for, they showed up with 80-90k in a series of fleets and steamrolled me. I didn't stick around to see if I could rebuild everything after they'd left because there was no way I could catch up if they kept at it.
If the game I just lost conclusively is any indicator, I should've been on a war footing from the get-go with the sole focus being victory (or at least survival) through power. But even then I don't know how I could have amassed quite so many forces. That, or I did a terrible job of diplomacy and while I had plenty of friendly races who would trade just about at will, etc., did not have serious defensive arrangements. Perhaps the idea is to make absolutely sure marauders don't unite. I guess I'll see in time...
Think I'll set it up the next map in light of all this. But ...ow. What a beat-down.
Not sure how much this will help, but my go to starter race(with explanations of why):
They are the Hani, home system of Anuurn. They are lion people.
Traits:
Slow Learner(leaders will still reach level cap)
Sedentary(For a penalty, this ain't bad)
Adaptive(more planets to inhabit)
Industrious(minerals are life)
Ethics:
Xenophobe(for the starbase influence cost reduction, the sooner you can have multiple constructors out taking systems the better)
Egalitarian(more influence, for more starbases, plus consumer goods really cost alot mid to late game, so reducing those is good)
Pacifist(more resources, more core systems, both will help alot)
Oligarchic government(elections 20 years, so don't have to deal with it too often, and you can pick who you want to win...note, democratic has nice bonuses, so really good too)
Civics:
Mining guilds: more minerals
Functional architecture: Cheaper buildings makes minerals go further
There are alot of other ways you can go, some probably better(try the inward perfection civic, very interesting, very powerful depending on playstyle), but this will give you a good start. Get a second science ship going as soon as you can afford the new leader. As soon as you have a good pool of influence, get a second constructor going and expand like mad. Try to colonize one or two more large planets as soon as you can, then slow down colonizing a bit and let those colonies grow(every new planet colonized raises research cost and unity cost). First tradition should be Discovery(I think always). Then Adaptability, then Expansion. I like Interstellar Dominion as my first ascension ability, as it reduces influence cost of starbases again. Reddit is a good source on advice to fit your ships the best way.
Hopefully that is at least a little helpful.