Astro turf

Best bet is raised beds.

I’d also go with raised beds. You have no idea what weed suppression chemicals might have been put down and you’d really have to dig down.
I’d test the soil first to see if it was ‘clean’ then if it is, put a layer of thick cardboard down before filling the raised beds.

How deep is the sand? Can you just dig it in, along with a good layer of compost? It may change the pH of your soil slightly, depending on how much there is, but I doubt it will have muc effect?

Can you get the soil tested?
Just ordinary sand could be dug in and could help improve the soil if it is heavy clay. However, it could have chemicals mixed in it too.

Well done for removing this fake grass!

AreWeThereYet

How deep is the sand? Can you just dig it in, along with a good layer of compost? It may change the pH of your soil slightly, depending on how much there is, but I doubt it will have muc effect?

Yes, that is what I would do. Will give it better drainage. But I would wait a couple of years for veg, due to the concerns raised by J52 about weedkiller.