Simple advice when traveling anywhere, never assume.
You’ve mention Hilton Paddington. Is that choice of where to stay based on points?
Although I don’t fly VA’s Upper Class I do fly the airline’s Premium Economy. Virgin Airline planes arrive and depart from Terminal 3
Reality is you will arrive, then have to clear security. which can take time. It’s a bit of a jaunt ( walking and riding the people movers ) to get to security. I’ve gone through security in 60 minutes, 45 minutes and in 10 minutes…seems dependent on staffing and how many other planes landed at the same time.)
My flight is nearly always the same arrival time as it’s the VA overnight flight on LAX to LHR.
If you are staying at that Hilton you can board the Elizabeth Line or well in advance like December 2024 book and pay for Heathrow Express tix.
Elizabeth Line is newer, cheaper and takes 30 minutes to get to Paddington Station. The HEX takes 15 minutes. Given my flight time and I love London I always opt for the HEX. It’s my comfort zone. That and the reality that where I stay is a 15 minute stroll from Paddington.
As far as what to see that’s up to you.
From Paddington you could board a Circle Line Underground train that would get you to Westminster Station in 20 minutes. Its well signed when you get off. Exit onto the street and you’ll be in the shadow of Elizabeth’s Tower with the Big Ben bell. About as iconic as you can get.