If you're f2p, look up an endgame build for the role you want to do - heal or dps, and just work towards getting that the way you see fit. Respecs are free until lvl 15, after that they are quite costly and you can save yourself the gold if you just get your endgame build right off the bat.
Not really a good advice. If you're pure f2p you have to postpone group activities until you farm enough resources to get at least basic runes. Going straight for endgame group build when you got level 2 or 3 runes is not a wise decision, no one is going to take a person like that into a group and even if your build was best possible and by some miracle you found someone willing to take you, you'd still do bad.
Pure f2p --> start with most efficient FARMING build. Period.