Turtle style in PvP is a bad idea in general. Eventually your attacker will overcome your defences that's almost a guarentee.

Multiplayer is mostly rushing hard and fast to either beat your enemy if possible or to at least put him in a stalemate.

The standard for Player vs Player is a 5v5 random single huge map with settings on fastest. This means that the enemy homeworld could be about 1-4 jumps away. I say 1 because that does happen at times.

The TEC are the easiest to get into.

Starting capital is usually a Akkan Colony ship for early expansion and economy bonuses. May change depending where your position is on the map.

Corvettes are the mainstay frigate currently in the early game so best you start spamming them as soon as possible if you're not in the eco slot (when you are between two allies to protect you). They are countered by flak though so best to start switching to regular frigates once the flak starts coming out.

Learn counters to various ships and etc. Keep playing and you'll get better at it.