How can I paint the stairs to the basement without them being slippery

check with local hardware store. They make a non-skid paint and there are also techniques to add sand to your paint.

Non- skid strips, also drawer liners cut to shape and clued

Sand down the glue so the treads are smooth. Then when you paint them, scatter a light layer of sand on the treads. It really works!

There's also a textured paint I've seen at Home Depot that does the same thing.

You can get a paint additive from Rustoleum especially made for that purpose. It's available at most big box stores.

Lowes and Home Depot sell a paint with grit in it to prevent slippery conditions.