>>712581084
I'd get an 8.5 (I have size 11.5 feet, an 8.5 deck is a nice all rounder for me), but you can make the most of the 7.5 for getting your basics down like pushing, kickturns, etc. I didn't really start until I was 29 (going to be 34 this year) so here are my tips:
-pads. Wear pads. You already look like a dork but pads will save you from the early hard slams that will scare you away or leave you needing to recover for too long to progress.
-stretch/do warmups. You're going to be using all sorts of weird leg and core muscles you probably never have before, so get ready to feel a real burn, and be cautious about over-doing it early on and straining yourself.
-spend a looong time learning how to push and just rolling around on flat. My rule of thumb is that you should be able to to a running throwdown and be able to stop or run off your board a top speed before you bother with ramps.
-stay low. The instinct when you're in danger as an adult is to stretch your body out to find something to grab and steady yourself. This is the worst position to be in on a skateboard because you'll be top heavy, unstable, and likely to hit the ground very hard if your board slips out from under you. Always get into a bit of a squat when you're doing something scary and dangerous. Your centre of gravity will be lower and more stable and if you slip out, you're closer to the ground and more likely to sort of roll out of the slam naturally. It's a hard habit to learn but always have it to mind when you're scared.
-try endovers and monster walks to get used to pivoting the board. You can look up what those actually are, but they're a simple exercise on balance and will get you used to making quick adjustments.
-pace yourself. You might want to go super hard, super fast, but don't. You need to build up strength and balance and confidence and you're not a child any more, so take it handy. Maybe no more than an hour to and hour and a half 3 times a week to start off.
