If you're planning on a shifter then you should begin by prioritizing HP for survivability. Ensure that your natural wisdom (out of form) is high enough that you can get max practice sessions when ranking in form because the check goes off of unmodified, natural wisdom. Mana is an afterthought, it'll come on much of the gear you're looking for anyway.

Prior to gaining a form you should look for wands, talismans, or one of the marble pieces (ask about them in game), so you can cause damage. Also, I suggest picking 1 defense spell, scales of the croc, hide of rhino, chitin of crab, working on only one because they are prerequisites for an edge respective to each. Pick 1 offense skill, claws of lion, horns of bull, fangs, and practice it to augment your melee. The reason I suggest picking only one is that saving practices to convert for trains can be handy.

The general strategy of prioritizing HP works until your mid 20's, give or take, because most people don't have a lot of ability to hamper your str or dex. As you go higher try to keep HP in mind but it isn't bad to sacrifice a little hp for +1 or +2 to your stats and or saves if you're fighting casters.

Lastly, about hit/dam. There are numerous spells and skills that can enhance them but in most situations the affect takes some effort to begin seeing noticeable results. You can add Beastial Fury or Relentlessness of the Jaguar or Brutality of the Shark, offense/water greater enlivens to boost your damage or hitting, you can use frenzy, chest beat (certain forms), war dance (certain forms), dragon's strength, ferocity, berserk (with a certain item), blood frenzy if you have certain forms, battaglia and canticle of the gods if you're with a bard, arestia if with a shaman, accuracy, bless, enrage (certain cabal/align) and maybe a few more. Some of these can be stacked with one another. I've seen some forms raise as much as 2 damage nouns on their peak damage if they're using many of these things combined but in most situations it isn't worth it.