Any advice on Traveling to UK + Europe Trip

Hello everyone!

I’m a 27 year old from Canada, and for my 28th bday this September I’m visiting UK, France, Spain and Italy. I don’t know where to begin though. I was thinking maybe I would make UK my base? And from there I train to France, from France I fly to Spain, and from Spain to Italy?

I’m taking a leap by using my savings to do this because it’s been my dream and I’m willing to let go of money because I can earn it back, but I do have quite a strict budget.

I this a good and cost friendly itinerary? Or is there anyone with a better solution with the order of the countries I’m wanting to visit ? Also, since I’m a solo traveler, any safety tips? And maybe suggestions on how to take nice photos of myself without being annoying to locals haha.

Any recommendations for must see places? Hours of the day it’s saddest to be at my hotel/bnb? How to make friends and where to go to make friends?

Other things: where do I buy pocket wifi or SIM card?I’ll need internet to go around and would it be useable in all 4 countries? (I’m guessing UK might have their own?) and in terms of public transport, how to get to the different destination places easiest, cheapest and by convenient order?

I have a Japanese passport, so any advice on what visa’s or travel documents to have, let me know as well 💖

Thanks in Advance!