Let me start off by saying that we've all been there. My first few games I started out on normal (or maybe even lower) and indeed got served by the AI. Especially the AI in Dark Avatar can be really daunting (in Twilight, it is still impressive but hindered by the very ambitious techtrees which the AI, frankly, wasn't built to handle).
For future reference, it can be useful to state what kind of map you're playing on. A Gigantic, All Abundant map, plays very different than a Tiny, Rare map. It sounds to me like you're playing at least a Medium or Large galaxy though, which a decent amount of planets, most of my suggestions will be based on this assumption, but most will be useful anyhow.
Judging by your post, and the previous ones you've made, you're pretty new to Galactic Civilization. It also seems that your enemies are not only stronger militarily, but also have bigger empires than you. So instead of giving military tips, I'll give you some economic pointers.
- The sinews of war are infinite money.
Civilization set up:
The Terrans are indeed a very fine selection, they have awesome Diplomacy (which helps prevent wars and make great deals), decent influence, good economy and very decent construction capabilities. What also helps is that they play very similar in DA (Dark Avatar) and ToA (Twlight), so if you can play them in one, you'll do pretty well in the other too. All races have some default bonuses (and penalties), but also offer spare points you can spend on extra abilities. Most of the given options are good, but some are better than others. If you are having a hard time keeping your economy healthy (if you play agressively, this is a must), you need to invest points into: Population Growth, Morale and Economy. More people earlier means more taxes, a better basismorale either increases your population growth or allows you higher taxes and economy... is too obvious to explain. Whatever points you have left, you can invest in anything you want. Also, don't forget to pick a fitting political party. Then start the game.
First thing you do when you start a game, is pick a tech to research. Whichone you ought to start off with can vary highly with your objectives and with playing DA or ToA, but techs which boost population growth, diplomacy, economy and morale can be great early achievements.
When determining what to build first on your homeplanet, consider the bonus tiles. I usually start with a research building, but a factory on a manufactoring bonus tile can be a great first start too. It is often wise to BUY your first few buildings, rather than build them. When you're done messing around with your planet, go to the domestic policy screen and ramp up the expenses slider to 100%, there is really no point to having it any lower than that. The initial military/social/research division is quite playable, but you can change it once you get to know the game a bit better.
Set your flagship to "automate", it will find the anomalies on its own, do the same for your space miner.
Use your colony ship to find a GOOD planet. No, not that ugly rock called Mars, but a useful planet. (Class 10+ is much preferred).
Some basic instructions on galciv's economy:
The backbone of your economy is your population. More people, means more taxes, and more planets generally means more people! This means that the more planets you can colonize early on, the stronger your economy eventually will be. The Colony Rush is very important. Cranking out those colony ships ASAP is a high priority. The original colony ship design is pretty fast and has good range, but it is also more expensive than the minimum. If you know of nearby planets, build custom colony ships instead (you can design these in the ship yard), forget about engines, just a hull and a colony module is enough to do the trick, smaller hulls are cheaper (=better) as long as they can hold the colony module. Cheaper ships means less military production needed to produce them means faster shipbuilding, means more planets (if you do it right).
The downside of the colony rush is that it is almost impossible to maintain a balanced budget and still grab a lot of planets. To get you through the dark times count on:
- your flagship to pull in a few money-anomalies
- selling tech to minor races (and sometimes even majors)
- a very high morale (very low taxes!)
I'll explain the last one: People don't like taxes, it brings their morale (=approval) down, so they don't breed well with high taxes. But you need a lot of people for a good income. The trick is to not raise your taxes when you start slipping towards bankruptcy, but instead to LOWER them. Lower them till as many of your planets as possible (that still have room for extra population growth) have 100%. The reason is this:
- The planet's approval modifier is:
- 0 if approval is less than 21%. In addition, you lose 10% of your existing population per turn.
- 0 for approval between 21 and 40% (pop doesn't grow).
- 1 for approval between 41% and 75% inclusive.
- 1.25 for approval between 76% and 99% inclusive.
- 2 for 100% approval without the Super Breeder special ability or 8 for 100% approval with Super Breeder (Torians).
This means that with the Terrans, your planets population will grow twice as fast at 100% approval, than at 41-75%!
These are a few pointers, but it has already turned into a wall of text.
I therefore suggest that you read https://www.galciv.wikia.com/wiki/Galactic_Civilizations_Wiki
Of course, if you have a very specific question, you can always ask on the forum. Be sure to be quite specific though.