When frogs spit on you can you get warts?

No, this is just an old wive's tale- the worst that will happen is that the uric acid might irritate your skin a bit and make you itch for a while, unless you wash it off soon afterwards.
No way. That is an urban legend. I have never had that happen to me, nor has anyone I've ever met, so I think you're pretty safe. This coming from a guy who can't keep his hands off of reptiles and amphibians. Warts are caused by a virus, Human Papilloma Virus (HPV). Frogs and toads don't carry that virus, so you aren't going to get it from them.

Some frogs are poisonous, especially in the tropics. But they do not carry the virus that causes warts, though they may have poisons on their skin that can kill a you. One example is the dart frog.
Toads and a few tree toads produce secretions from granular glands that are located chiefly on the legs and back and associated with "warts". The secretion can be irritating to human skin and highly distasteful to predators.---Comparative Anatomy of the Vertebrates, George Kent

Frogs have warts. They do not produce warts