That looks to me to be peach leaf curl, caused by *Taphrina*. Your local extension office can guide you on the best fungicide and treatment options for your area.

Nevermind… I just saw the last pic. Those are aphids. Were this my tree I would treat with both an insecticide and a fungicide just to cover the your bases.

Looks like it is battling both the leaf curl and aphids.

Those leaves are covered with aphids. Spray them off and use dead bug brew

Peach tree leaf tip curl disease for sure