It's only been out for a couple days, give them time.
As to suggestions, expand fast, but not TOO fast. Having numerous planets SERIOUSLY hurts your empire's morale until you've researched a couple morale upgrades.
The second tech on the left on the bottom tech tree (I forget the name) is what you need to travel through wormholes.
Your initial corvettes aren't that good at space combat - research destroyers fast. Then make a few. Early on, one custom-made destroyer can usually take on whole pirate fleets.
Having big populations in each system is better than having too many systems, but be careful about settling planets with large morale penalties early. Those penalties apply to the entire star system. (By large, I mean 10 points and up.) Don't overlook that negative specials usually give pretty major morale hits, too.
Try to never have a planet fill up if you have colonizable planets in the same system, unless you can't take the morale hit the planet would give.
Smaller, more powerful fleets can easily beat lots and lots of smaller, lower tech fleets, but the computer will send hundreds or thousands of ships at you in 5-7 ship fleets. They can and will wear your fleets down, so make sure yours is capable of absorbing the losses.
Anyway, that's what came to mind right offhand.
ETA: Pirates can only spawn in systems with no sensor coverage. Parking a scout in every system in your constellation will prevent pirates from spawning behind your front lines.