Front derailleur adjustment is one of the trickiest things to do on a bike... the following assumes the derailleur is mounted in the correct position (inner plate parallel to rings, outer plate clearing big ring by 1-2mm).

First ensure the inner limit screw is properly set, by seeing if the derailleur rubs on the chain when in smallest ring/biggest cog. If there's a gap, turn the screw until it's as small as you can get it without chain rub (remember to allow a mm or so for some flex that will occur when you're on the bike).

Then secure the cable and shift into biggest ring/smallest cog and adjust the outer limit screw in the same way, ensuring the shifter is holding the derailleur against the limit screw.

Back off any barrel adjusters on the cable to a couple of turns from fully loose, pull the cable tight while the derailleur's resting against the inner limit screw, and finally tighten the clamp bolt.

Test shifting and tweak your barrel adjuster to minimise chain rub.