Trip to London, Rome

You can check flight prices/possibilities here:
https://www.skyscanner.com/

You might want to do a multicity (open jaw) trip, Into London and out of Rome, or the reverse if better price. Do a separate flight between. Only buy flights from the carrier.

The Rick Steves London guidebook describes and rates many sites, puts together agendas and gives many hints about transportation and food and much much else.

The Rick Steves Rome guidebook does much the same for Rome.

We can list off all those sites or you can do some research with youtube, this website or many others and then bring specific questions and we will help. I'll let others do the listing or you can look around the website

Hard to say about what is a reasonable fare, prices this year seem to be well above past years, and unless someone flies out of San Diego, it is different for everyone. June July will be peak season (though it seems peak season is getting to be nearly year round). You are probably in prime buying time for tickets right now.

I agree with looking at flying into one city and out the other using the multicity option.

For flying between Rome and London, you have lots of choices, many of them budget airlines. Whatever airline you use in Europe, be aware that if they allow a carryon bag, it is not like the US where anything goes, you must be under 10 kilo (22 lbs) usually and under a certain size, and they do check. Just price in checking a heavier bag, the total price will still be cheap.

In a week each, you can see plenty of things. London has a nice perk in that many of the public museums (British Museum, National Gallery, Tate Modern, V&A, and lots others) are free (a donation encouraged). However, many popular sights (Westminster, St Pauls, Tower of London) have a pretty steep ticket price.

In both places I would encourage at least one day trip to a smaller town accessible by rail.

For both places, I would suggest starting with Booking.com. It has a variety of lodging types from hostels to small hotels, to chains, to apartments. The map functions shows exactly where the place is at, important for being near an underground station. London will be expensive (well, being from San Diego, maybe it will look normal), a quick look, a well rated place is $200-$300 a night. Some cheaper, most more expensive. Rome, probably about the same. Keep in mind, lodging is by number of people, not for a room. You will probably be looking for an apartment or two rooms. You can check AirBnB as well, and other sites.

You are asking for a bunch of information, the above gets you started. Do some looking, narrow some options down, then come back and ask about things in London and Rome in separate threads, and you will get lots of help. Both the Rick Steves London and Rome guides have tons of info.

Was in London for first time in October and loved it.

Stayed at Hotel 63 on Bayswater Rd across from Kensington Gardens. Great location. Good prices and very very close to lots of public transportation. Small B & B.

In London loved the V & A Museum and across the street is a Science and Natural History Museum.

Kensington Gardens and The Serpentine is awesome.

Try Coach House Rentals for London lodging. They have an array of self-catering apartments in different neighborhoods. They provide a bit more service than an AirBnB. We were very happy with everything when we used them a few years ago. It's about as reasonably priced as you'll be able to find.

They also have one rental property in Rome.

https://chsrentals.com

Have a wonderful trip!