Here are some links that you could find usefull for a first digging. If you make a maquette, you can send me all and I will try to put it online to show you how it could look "live". It could be interesting also for you to look at some website and think of "how to improve design" or "remake" the design of some that aalready exist.

You don't need to know aabout HTML and CSS but it is a good aadvantage to know some stuff. I will not conver it here. Later.

First a post from an UX designer on Medium: 7 steps to become a UI/UX designer

Here is a free course about Web Design on UDemy:

I don't recommend to pay on this website, it is quite overpriced, but sometimes you can't find some stuff for free here, or as well on youtube

Here is a tutorial to design some websites from Steven Snell:

Making a website and an app is slightly different, but we may have to think about both from the begining.

And now some events about UX/UI in london:

I hope it could be usefull, I will let you know if I find more stuff :)