How do I implement a COD type weapon system?

I am racking my brain trying to figure this out, I followed the devsquad fps tutorials to get to the point Im at now. So at the moment I have two weapon slots, but each spawns a determined weapon and just hides one actor and unhides the next. Im trying to figure out how I should go about making it so these two slots can spawn different weapons depending on the level as well as switching the current weapon with a weapon from a pick up on the ground. Right now I have a pick up for the second weapon and the slot isnt available until the pickup has been collided with. All this pick up does is make the second slot accessible. Ive only been getting into unreal for a few months now so I have absolutely no clue where to even start.

Have a look here:

Admittedly, it’s just one of many ways to do it.