How do I get rid of roaches

Boric acid is excellent. If you want to get it retail, look for "Roach Prufe" at large hardware chains. Good luck.

Thank you I will look . Can I buy just boric acid.and also where do I put it ?

Boric acid is cheaper than Roach Pruf. Get it at any drugstore. Spread a 1/4-1/2" line along the baseboard.