Questions about "ь", "ы" and "ъ"

I have been learning russian for a little over a year now, but one thing that's stuck with me is the usage of ь, ъ, ы.

I tried searching and watched multiple videos on how to differeniate, when to put it and how to spell it correctly, but it was to no avail.

If someone can reply with a Very detailed explaination, please do as I'm very lost. Спасибо!