Note that your empire age would get reset if your restarted because, if you`re empire age after all, not how long you`ve been playing.
About free account races:
Terrans - best balanced race for free account, good ships like P.thor and Hercules, and heaps of money by producing food.
Miners - no wonders, as miners, they *are* the best money making race on the game, with it`s 1000% bonus on mineral generation and 15% bonus on taxing (only positive taxing of all races). Though it ends like that, you can be a trillionaire after a few months of play, though they got the worst ships on the game, maybe to be rivalized by the Collective. In the contrary as everyone says, they are horrible on defending and often use ship spams to win battles, but they got quite good ships to win offensively if you`re a good stacker or got luck with spamming. Their main weapon when fighting is of course, getting near someone at up to 1 mill power with a fleet you know you can win against defensively, build HEAPS of Lyth with dummies (I usually only have Lyth + 4 dummies), maybe use some artifacts to gain turns and build more of them, then counter on careful and grab planets. Just note that they don`t got that good build rate at all and their big ships and starbases stink.
Collectives - okey, near collectives, the miners don`t have that bad build rate at all. They can make a lot of money producing food, but they can`t explore for good planets, only steal, don`t have enough missile ships neither big ships as dreadnoughts or starbases. And also can be killed when someone wins a battle against their homeword. So basically play only if you like to play on lower PR and a challenge.