Where to get physical copies of the manga internationally?

Hello, i've been reading the manga for years now and always wanted to get the physical copies but didn't have the money to do so. Now that i'm planning to put away some money for them i wanted to ask where i can buy them preferably in English. Tried to search online but i never bought physical manga before so i got confused to the point of creating a reddit account.

(I saw some Japanese sellers but i really prefer buying in English since this manga is the reason i learned English when i was a kid so i could read haha)

I would also really love to know the average price of buying vol 1 to 28 so i can calculate if i'll have to wait months or years to buy them lol

(Sorry about the mistakes, not the best at English)