straddle press to headstand from straddle stand against wall, then pike.
you can try to skip to doing negatives against the wall with a hold as low as you can go.
the farther away your hands/wrists are from the wall, the easier it will be. too far and they start slipping or your wrists can hurt because of the flexion angle so you can turn out your hands to the side to relieve the pressure. You can also turn them back but they slip more this way.
you can also use parallettes if it kills your wrists too much.
straddle/pike compression is crucial to make the press easier/more efficient as is shoulder flexion flexibility