I am going to make a cheesecake but I bought the wrong base for it. I want to make good use of the ingredients that I bought. Does cream crackers make good cheesecake base? Or should I make my own base?
Cream crackers are savory, not sweet, so they wouldn't be a good choice for a cheesecake base. Their consistency also isn't right for a cheesecake base, you would be best off getting the right kind of crackers or biscuits for the base. As for the cream crackers they are typically eaten with cheese on top or some other sort of topping, or you can crush them up and use them as breadcrumbs.
You could but, after finely crushing them, you would need sugar and a bit of salt, along with the melted butter. To resemble digestives, you might want to use muscovado (or demerara, turbinado).
There are cheesecake versions that have bases that are not particularly sweet and are made dough-like, from flour, sugar, butter, and eggs. Here's an example of one you can make from pantry ingredients.
While I've used all sorts of baked cookies/biscuits for my bases, my favorite, and the one that gets rave reviews, uses shortbread and my go-to brand is Walker's. For proportion, I use about 150 grams to 3 tablespoons of melted butter.