What are some good quality of big and tall products to buy to replace, and pare down my stuff?

I have plenty clothes, and books that I would like to replace with something better .

Like lots of size 13 socks and XXL underwear and shirts.

I would like to buy excellent clothes and reference books to replace with something better. Does not have to be cheap.

Why? I watched many episodes of Horders. Also I am spring cleaning .

What are some more tips in de-cluttering my apartment? I would like to pair down to a backpack of stuff and furniture. I am going through papers, junk mail, and receipts.

If you where to start from scratch what would you fill up a backpack with.

I am willing to put most of my stuff in a storage locker, or to sell, or give away. Can you recommend one in Red Deer Alberta?

May you please suggest a book, or YouTube video, on pairing down stuff or tips

Advice like give away appliances that I have not used in a year is welcome.

Humor not welcome for this question.
I would like to have everything I need in one back pack, and to sell most of my other stuff or give away.