How to treat both uti and yeast infection at same time?

You would: most likely need an antibiotic for the urinary tract infection and an antifungal medication for the yeast.

Treating both: If both proven- antibiotic and anti fungal. Please note that not all urinary fungal infections are to be treated. If significant instrumentation/ stents, catheters, etc over last few weeks, may need further work up. Hope it helps.