Hello mr sir, I am writing this from school so there might be some errors as I cant test it, but ill see what I can do.
We'll start with the radiant part, you only need 2 things, your script_model and your trigger. - Create a script model and give it these KVP's "targetname", "item_pickup1". - Now create a trigger_use ( or a trigger radius if you don't want the player to have to hold F) and give it the KVP "targetname", "item_pickup_trig1".
That's it for radiant, now open up your mapname gsc located in root\usermaps\<mapname>\scripts\ (path could be different, not home to check). Open the larger size file (Not sure if that matters, but it works for me) and add this code to your main function somewhere
Now at the bottom of the file add this
I wrote this script while in school so its untested and im limited in time, goodluck mr sir.