Hi I was wondering if you switch in and out again after using first impression can you use it again?
Yes. It's basically just a fancy fake out. I know this for a fact because Guzma used it to kill my Hydreigon in the battle tree. It failed the first time and it came in for another round after I activated its ability. It does not work after the first turn tho. Also, it's in bulbapedia
https://bulbapedia.bulbagarden.net/wiki/First_Impression_(move)
it works like fake out any time you time you switch in golisopod, you can use FI as long as its the first move you select
Source
Hope this helped!