Unzip the file to a folder, and double-click on the “Marlin.ino” file. Tab over to configuration.h, and ensure that all of the lines at the website below match.
The rest is pretty self explanatory (verify Port in the Tools menu, upload)
Second: confirm wiring… 2B and 2A are a pair, and need to go to their own coil. likewise with 1B/1A. If this is the issue, the motors should not move at all; but I’ve seen weirder things.
Third: Are all of your Microstepping jumpers in place, under the Pololu drivers?
Fourth: Have you calibrated your Pololu drivers properly?