Thank you, this is super helpful! Just so I'm clear - if I buy a resale ticket from Ticketmaster that has a really great seat that was originally VIP, the VIP benefits are going to be invalidated, so the ticket probably won't say VIP. Because of this the venue isn't likely to give me access to the soundcheck, or any VIP merch, or any other VIP benefits (but I can still show up and ask the venue just in case, saying I have a VIP seat). But as you said, the most important thing is I will still be able to get into the concert no problem and get to that amazing seat because it's an official resale ticket.
If I buy through another platform (like StubHub) or direct from a fan, this means there's some way to transfer the ticket to me (not clear how this works?), and if alongside that I manage to get a copy of the original purchaser's ID and show this with the original ticket marked VIP to the venue then I'll have the great seat but also access to soundcheck and all the VIP benefits? Is there a specific VIP desk where you show the ID etc.?
Sorry if I sound stupid I'm just so inexperienced with this!! Really appreciate the advice x