if you don't know Ohm's Law, you should learn it, the basics are really easy. it's a simple proportion. when i was 8 years old (a half-century ago) i learned to draw this mnemonic so likely you can too:
in electrical engineering, E is short for "electromotive force" which we all call Voltage (volts). I is current (erm, probably because the letter C means Coulombs, or capacitance. tough luck just memorize it.) R is resistance, units are Georg Simon's last name.
use it thusly: if you want to know E (voltage) put your finger over the E. what's left? I (vertical line) R. E= I * R. want to know current (I)? put your fingertip over the I (over the unknown variable), what's left is E (horizontal line) R. I= E / R (E divided by R). shut up and do it.
(Ohm, Volta, Ampere, Coulomb are all old dead white guys. go figure. Marie Curie couldn't [initially] do physics in France without her husband around; Lise Meitner got screwed out of a Nobel Prize by her lab-mate-turned-nazi-collaborator Otto Hahn. life isn't often fair.)