Bodybuild

which exercises will help me build pecs? and i find that my left
pec is more developed than my right pec....how can i even this out?

No doubt, the basic ones. Bench press, dumbbell flyes and weighted dips.
You need to pay attention to each rep. Slow, controlled movements.

Supersets work great.
Do first 3-4 sets of bench press, then - 2-3 supersets - inclined press + fflat dumbbell flyes, and then 2 supersets cable crossovers + parallel bars dips

Try to do 5 sets of parallel bars dips each day during the week.
Helps a lot.

Go to the basics:

1. 5 sets of bench press
2. 5 sets of inclined bench press
3. 5 sets of dumbbell flyes
4. 5 sets of dips between bars

Bench press - 3 x 8
Inclined dumbbell flyes - 3 x 8
Declined barbell press - 3 x 8
Cable crossover - 3 x 8
Lying dumbbell flyes or machine flyes - 3 x 8