Can one use sharp sand to make concrete?

As per title, one would like to make a base for a shed. One has lots of sharp sand already in the garden so would like to use it rather than get rid of it and buy ballast or whatever.

So, can I make the base using this, obviously with cement too. How much cement would I need to mix in?

The base I need is about 3.3m x 2.7m at around 4 inches depth on average. Is that about the right depth, I could make it deeper if need be. I also have loads of stones / bits of concrete I could / want to mix in to avoid having to get rid of it. I assume that is cool. They'd go a few inches down leaving the top 2 inches just sharp sand and cement.

I'd put a wooden frame around and then tamp it level with a long piece of wood. Neighbour suggested smoothing the surface off but does it matter as I won't be able to see any of the base afterwards. It'll be covered up by bushes and a new patio going up to the shed doors.

Thanks for any advice!