What genres or types of series do you like?
Master Zik
list is good, but i'll add some other options
Something like Pluto by Urusawa is only 65 chapters, Monster is 162 and has an anime you can watch to clear up any confusion. There's also 20th century boys by this same mangaka.
Sports manga there's slam dunk, Haikyu, and Daiya no A which has 2 parts, the 2nd part is still ongoing. Those are sports manga on the more realistic side. It's historical fiction.
A good entry shonen that's complete is Demon Slayer.
One Piece is a good ongoing one. It's super long, it's an essential shonen, and the good thing about it is that early in the series, the panel layouts are very simple and clean, but as the series progresses become more packed and dense, but hopefully by that point you're used to manga to where it's not an issue and you can watch fights on Youtube for additional clarity. You can also see in that series how manga's evolved from the early simplicity to the current day panels and art.
Everyone watches Yu Yu Hakusho, but it's probably a good entry point for reading as well, with really simple panel layouts that are easy to follow.
Bakuman is an interesting one, it's by the same duo that did Death Note and is an inside look at how manga is created.
Ares is technically a manwha but is in a classic manga style. It's is a series
@tdogg2k recommended to me that I enjoyed a lot. It's also a historical fiction taking place in ancient rome.
If you like cooking and food Shoukegi no Soma is fun.
Koe no Kitachi I think the english name is A Silent Voice is a romance / Drama series about a bully and a deaf girl and how their relationship evolves. It's very sad and the movie is on netflix currently it's short with only 62 chapters and a nice change from action series.
Jujutsu Kaisen is the hot series right now. It's still ongoing, but will probably end pretty soon.
Chainsaw man is a completed with 97 chapters. It's unique and very good and getting an anime soon.
It's really all about what types of stories hold your attention and getting used to reading panels
Korean manwha are easy to get into cause most are full color and you read them left to right like english for those I like
Solo leveling
Tower of God
The Gamer (not great, but simple and entertaining)
Wind breaker (it's about cycling)
Bastard (if you like horror)
Noblesse (not the best, but complete and pretty compelling and very easy formula to follow)
Hellper (need to go back and finish this myself, but was a really interesting story and art style. I think it was originally made to promote a clothing brand)