JBird said..
I surf all the time, but just getting into sup boards. If you have any advise I'm all ears.
You must prepare mentally to be a beginner again. Prone surfers (I was one) often do not anticipate how prone surfing does not prepare you to standing up on a SUP and using a paddle. Especially on a 8'5", which will be great after some time but require a decent paddling technique to master the row effect.
Plan to train on flat, glassy water (chop is very hard in SUPing). Then start with gentle small waves and alternate with flat water session to train for the points you have a hard time.
Your surfing expertise (wave reading, positioning, how to pup for speed, ...) will definitely kick in after the basic paddling skills will be learnt, but will not help for the first sessions.
So it should be OK, but be prepared for some learning curve...