Learning to ding on a DW board should be all good, really any board will do! Some like the longer boards might come of the water a little earlier while shorter might eel nicer when pushing some turns.
Best thing to really help when learning is oversize the wing a little as being under powered sucks.
I do have to be honest and dinging on the longer boards kinda sucks after a while and besides getting up easier they just don't feel as nice. Great for maybe the learning like you want but long term smaller is better IMO.

5ft

5'10

7'2