@johnreffitt1962 does the amp have reverb? If not you probably wanna start there.
Then I’d say probably delay.
Then maybe an octave pedal, which I reviewed several here:
Or an auto-wah. (I need to do a review of some.)
Danelectro makes super-cheap pedals that harmonica players seem to be fond of. Boss pedals are great, a bit more rugged, a bit more expensive. I could talk about effects pedals all day, lol…