Hello dear English friends.

Bad stuff happened to me, so I decided to do a solo trip starting in UK. It's the first time I go somewhere without anybody.

I'm arriving at St-Pancras via Eurostar mid-July at 7AM. I plan to immediately take a train to Cambridge, see what's nice (if you have any suggestions?) during that day, and come back to London before the evening.

In France, we do have "SNCF connect" app to buy national train tickets with our phones, but is that possible in UK, as there are many privatised compagnies? Is it expensive, does it take a long time, and until which late hour can I take the train to come back to London?

Back to London, during a few days, I plan to watch "Romeo & Juliet" at the Almeida, visit Highgate cemetery, spend an evening in Soho, try the National Gallery or/and the British Museum (I guess I'll have to take tickets in advance/come early?)... maybe some other things (if you have another suggestions). Is it easy to rent a bike, and drive it without dying in London?

Then I'm leaving London by train for Highclere (yes, for the Downton Abbey castle, sorry for being a cliché) but I guess I'll have to manage the distance between the train station and the castle, and suceed in actually having a ticket or idk to get trough the gates of the domain. Then again, Salisbury for Stonehenge (sorry, cliché again...), where I guess I'll have to arrange a bus to get there (and maybe a guide?). And then again, Southampton for all the Titanic-stuff.

I don't know if I can travel by foot or bicycle from Southampton to Portsmouth (or maybe other little towns there if they are cute and using the train for Porsmouth?), where I'll finally leave the UK via ferry to come back to Cherbourg, France (why the hell does it cost 125€ for a single passenger without car??).

Are there some things, tips, etc. I should know, or do you have advices to the friendly but maybe ingénu tourist I am? Thank you and have a nice day!

(sorry for my potato English)