Collecting item from the seller - what's the etiquette?

[Plumpciousness]

My first time collecting from a seller. Is there a particular etiquette other than being polite and actually turning up? I've got the address and we've arranged a date for collection. Do I just turn up with the money and appear grateful? Don't have to let them know I'm on my way and I'll be there in 20 minutes sort of thing? And only communicate via Ebay, don't give mobile numbers?

And for safety should I let someone know the address I'm going to?

TIA

You are massively overthinking it.

Contact the seller, arrange a mutually convenient time to collect,
be on time,
have the money (exact change)
have a quick check that the item is as described and take it home.

Agree with Eternal, it really is that simple

And for safety should I let someone know the address I'm going to?

well, you can if it makes you feel better. What exactly do you think will happen though?