each title level you get some respec points for IP, so if there are some skills you need to reset now go ahead. but don’t get ahead of yourself since you might want to save some for when you are nearing endgame.
for agent the strongest build is to fp metaphysicist, get buffs and cast the top pets you can, then fp trader and use drains to boost AR and keep your pets up. later on you will need to use fp doctor or adventurer for more solo survivability. This is a lot of work especially if its your first character which is why I highly recommend rolling an easier profession to learn the ropes before diving into agent which is the most complicated profession and requires the most nano programs. Specifically fixer/engineer/shade/keeper are great for solo leveling and only require a few nanos. if you plan on sticking with agent just get used to sneaking past stuff in SL for progression.