Well, first, find a good manga app from your app store. Some popular ones are Manga Rock and Webtoon. Once you have it installed, look for the search bar and type in the name of the manga you want. Make sure you have a stable internet connection for smooth reading.
Webtoon is a popular option. It has a variety of free manga and comics. But keep in mind that the selection might be limited compared to paid services.
Well, legal manga apps usually have partnerships with publishers and follow copyright laws. However, there are a lot of shady apps out there that violate these laws and are definitely illegal.