Hello,
"Bath" is a noun. I have a bath every day.
"Bathe" is a verb meaning to immerse yourself in water. It can be used when you mean "have a bath" but in my opinion it usually implies swimming rather than washing. I love to bathe in the river.
"Bathe" can also be used with a direct object. You should bathe the wound to avoid infection.
Note that "bathe" loses the final e when a suffix is added - I enjoy bathing in the sea.
I would use "bath" as a verb when discussing washing a baby. We must bath the baby tonight. This could just be a British thing, though.
"Bath" and "bathe" are often misused, even by native speakers (like "breath" and "breathe") so don �t necessarily trust an online source!