How do i make a command that gives a user a role? for example: (prefix)@user @role
It very much depends upon the library you are using. Are you using Discord.JS? Which version, I assume 12.x. Your bot needs permission to set roles as well.
I don’t think the Glitch support site is the ideal place for Discord Bot coding questions, maybe it is perfect but it seems that the two major Discord guilds related to the topic would yield many more answers for you.
I think a search of the Internet would also yield some videos and tutorials with examples you could copy.
The official Discord.JS server could help you more, as it has a lot of people experienced with the library.