I haqve just downloaded Zcash Claymore and in readme file there is something like:
Set the following environment variables, especially if you have 1-2GB cards:
Should I set them if I have ASUS rx 480 4gb? Where should I type it?
I cant say for sure but I will tell you that I added the variables in on mine and I run RX-480s and RX-470s.
Where did you typed them in?
On Windows, you should set them in Advanced Settings / Environment Variables. Hit Win+Pause keys to open the dialog box with OS Info. The Advanced Settings link is on the left pane.
You could use this guide:
But where should I typed yhem in if I use Linux?
depends your flavor of Linux. See some help here if you use bash. Best is to make the settings permanent.