but it says I am in limited User because I buy from shop. whenever I click add friends a menu appears & it says. I can't do that. I have no access to it. Please help me to go through this problem.
Do you have Steam installed? If you do the following when steam is open and CS:GO is installed it should work.
Open steam
Go to bottom Right Corner of Desktop and find the black and white steam logo.
Right click > Friends
It should bring up a box that contains what should be your friends list.
at the bottom you should see "+ Add Friend"
but it says I am in limited User because I buy from shop. whenever I click add friends a menu appears & it says. I can't do that. I have no access to it. Please help me to go through this problem.
You may need to Download steam > Activate product code once steam is installed and open - download the client again if steam can't locate CS:GO after this process.