The ATC is an enhancement of FSXs and that’s always been a little ropey. Plans are in order to improve it, but still …
Why not look at VATSIM or IVAO ? It’s a little unnerving (okay, it’s dead scary) talking to a real person, but it’s much easier after a couple of flights.
Two rules ; don’t start up either on the runway, and when you want to try it out pick somewhere quiet (occasionally there are beginner sessions), not Heathrow on a weekend evening. In quieter places the ATC has more time to assist you with problems.
They show up in built ATC for what it is. It’s not that it’s terrible or anything, the other sims aren’t any better, but it just doesn’t have the same feel about it.
A good place to connect and just look is the maintenance area just south of the Runways at Gatwick. Great view, usually traffic, and listen in.