If you want to read comics online legally, you have more than one good option. Comixology is still one of the most useful all-around ecosystems through Amazon, especially for mixed reading across comics, manga, and graphic novels.
Comixology remains one of the best all-around choices because it combines store access, a subscription option, supported Guided View reading, and a large cross-publisher catalog.
If you want breadth, Comixology Unlimited is strong. If you want deep publisher-specific catalogs, Marvel Unlimited or DC Universe Infinite may be better.
Shonen Jump is often the best pure-value option for mainstream manga readers, while Comixology Unlimited works better for mixed reading across formats.