Board purchasing help


hey guys
Looking at learning to surf so need to firstly buy a board!! Any suggestions/advice would be awesome.

I have bodyboarded my whole life (even used to compete in my teenage years) plus did Nippers for 10 years so I would say I am a fairly experienced waterman. Ive always been obsessed with bodyboarding so I’ve never really tried surfing - these days I really have no motivation when the surf isn’t pumping so thought i’d bite the bullet and give stand up a go for when the surf is a bit smaller.
Im 6ft and 120kgs (I am a large human but have a reasonable fitness level)
I snowboard at intermediate level and skate very poorly!

I have used my dads foam Mal thing once or twice (I think its 10ft?) and was thinking getting something similar.
Anything I should be looking for or anyone know where to pick one up cheap??