Mellow

https://www.mangago.me/read-manga/save_me/

https://www.mangago.me/read-manga/an_uncomfortable_truth/

https://www.mangago.me/read-manga/dark_mortal/

Oh sorry i didn't see your full text

https://www.mangago.me/read-manga/heads/

https://www.mangago.me/read-manga/spy_x_family/

https://www.mangago.me/read-manga/kemono_jihen/

https://www.mangago.me/read-manga/brutal_satsujin_kansatsukan_no_kokuhaku/

https://www.mangago.me/read-manga/hokuhokusei_ni_kumo_to_ike/

https://www.mangago.me/read-manga/windbreaker/

https://www.mangago.me/read-manga/aragane_no_ko/

https://www.mangago.me/read-manga/satsudou/

https://www.mangago.me/read-manga/red_blue/

https://www.mangago.me/read-manga/gokurakugai/

Here ^^ but it doesnt contain romance. Hope thats okay :D

Akatsuki no Yona

It's hilarious how many manwhas were posted in answer lol

I started reading manga with One Piece but I'm guessing that's a bit frightening (so many chapters...)

I don't really know what your friend could enjoy so I'll name a few shorter classics of the shounen and shoujo genres :

https://www.mangago.me/read-manga/fullmetal_alchemist/ (warning: first page shows a missing limb)
https://www.mangago.me/read-manga/alive_the_final_evolution/ (the drawings are not so good at the begining but it gets A LOT better very fast - covers very heavy topics relating to death so make sure it's not a touchy subject for your friend first)
https://www.mangago.me/read-manga/eyeshield_21/
https://www.mangago.me/read-manga/ouran_high_school_host_club/ (the anime is also very good but it doesn't cover the whole manga, KISS KISS FALL IN LOVE forever)
https://www.mangago.me/read-manga/tokyo_ghoul/ (warning: coffee date leads to death and cannibalism)
https://www.mangago.me/read-manga/hibi_chouchou/

Agh, typo, I meant manhwa, curse my fingers

I started my manga journey with hirunaka no ryuusei
https://www.mangago.me/read-manga/hirunaka_no_ryuusei/

Great art, love triangle, second lead wins, easy to read. Totally a great recommendation for a new beginner who likes romance! It also has a LA. If they not interested on reading yet, they can start by watching the LA first. And after hirunaka no ryuusei, they can continue to another works of the same authors,
https://www.mangago.me/read-manga/tsubaki_chou_lonely_planet/

Great story line too.

Ao haru ride also a good starter too!
https://www.mangago.me/read-manga/ao_haru_ride/

i just ctrl and scroll wheel to zoom in and out :)

i found out how to zoom out

well i read them on pc yes, is it more uncomfortable than on the phone? also yes but since i broke my phone pc it is