ConqueringWolf,
Welcome to the Metaverse! I think you'll find the game fun and challenging. A couple of key things to watch for:
You don't have to build everything! This is one of the most important things to learn in this game. Important things to build are Soil Enhancement, Habitat Improvement and Entertainment Network in the early game. These will increase the capabilities of your planets to hold more population, thus give you more tax income.
Morale is extremely important in this game. At 100% morale, your planets have a population growth bonus. At 50%-99% morale, you increase population. Under 50% morale and you lose population, plus you risk your planet rebelling! Be very mindful of your overall morale as well, as you can lose an election (after you change from Imperial government to a higher gov't.). This will cause you to lose all of your gov't party bonuses.
It is imperitive that you try to get as many planets in the beginning of the game as possible. The AIs start out knowing where all the Yellow stars are (the ones with the good systems), so you're automatically at a disadvantage here. Grab as many yellows as you can as quickly as you can. If a yellow system has more than one planet in the system, only colonize one at first. The AIs can't get that system once you've got it and you can always colonize the rest of the planets once you've finished getting the yellow stars.
Start out by playing a Cakewalk game to learn. Trust me, Cakewalk is not a good name as when you first play this game, it's tough.
Watch the AI's attitude toward you! If an enemy becomes Cool or Wary of you, try to give them a gift of a technology or some BCs. Once an AI gets ahead of you in strength, they will try to destroy you, so you need to keep them happy as long as you can. Send freighters to trade with the major AIs, that will improve relations greatly and keep them from going to war with you.
Watch your military rating. You need to not be in the bottom of the group in this or everybody will try to take you over. Starfighters are crap as a military ship, but in the early game they will make you look like you have a powerful military...a paper tiger if you will. Be warned, a starfighter is terrible in combat and should only be used to boost your military rating in the early game.
Don't worry about not getting all the Trade Goods in the game. Try to get one or two if you can. Otherwise, trade for Diplomatic Translators (if you don't build it yourself) and Gravity Accelerators. If you get a Trade Good from an AI, you can't trade it with anyone else, but you get the benefit from it. The boost to diplomacy and speed is very important.
In your first couple of games, I suggest using the Populist party and picking +50% Diplomacy. The higher your diplomacy is, the easier the AIs are to deal with. Sell techs to AIs when you can. Don't be afraid to sell your military techs to them, they will eventually get them anyway so you might as well get some money off of them for it!
When selling techs, go for a longer term agreement, ie sell something for 50BC for 20 months instead of 100BC for 3 months. AIs will give you more total money if you spread the payments out, and if you sell the same tech to everybody, you can really rack up the money in your treasury!

Be careful with selling techs, though...don't get a large treasury (best guess: over 3-5,000 BCs) in the early game or you'll get an anomalous score when you try to submit the game to the Metaverse.
I hope some of these hints will help you enjoy your game and do well.
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