Recently i have been trying to make a gunslinger on dnd beyond but ran into not being able to, none of the equipment or any of the feats and skills wont pop up when i click on fighter and go through the process of making it. All i get is the basic fighter stuff. How could i fix this?

1. The gunslinger is a subclass so you pick it at third level
2. You need to have critical role content enabled when when begin character creation
3. If you haven't purchased any content, then only the SRD options (plus gunslinger at 3rd level as it's free) will be available

I bet it is the second thing Dave mentioned. A lot of people miss those toggles.

Also, annoyingly it seems if you go past the toggle stage, then go back and enable them, the changes don't seem to propagate forwards

That's more of a caching issue. Spells have the same problem some times. Just refresh.