
Where i can buy this manga?

It depends if you want it digital or physical! Digital is easiest right now since because of the virus most places in Japan aren't shipping overseas. You can use PayPal to get it from RentaJP, if you google "Renta JP BL guide" there is a website with instructions for setting up an account. You can also get it from ebookjapan though setting up an account is a little more complicated, or CMOA, which I've never used. If you want physical copies, I'd say try ebay or yahoo auctions or any online Japanese bookstore. I know CDJapan, kinokuniya, or japonica market could order it for you too. Hope this helps, feel free to ask if you need more details!
Should i read this left to right or right to left?
Right to left
just follow the bubbles from the right :00