Ovulation prediction kit help

Lily • BFP on 1/22/15 ✨Baby girl 10/6/15 BFP on 1/17/17 👼🏻Angel boy 10/5/17 BFP on 1/12/18 🌈
Hello all! I'm on the last day of my period and want to get an OPK! Which is the best brand to use and when should I start? Should I also use basal thermometer?? Thank you!