Some free sites that offer comics similar to manga include Webtoons and Tapas. However, keep in mind that the quality and quantity of content can differ, and not all may have the exact style you're looking for.
Some of the relatively safe manga sites include MangaFox and MangaReader. They have a decent reputation for providing content without major security risks.
One of the legitimate options is Shonen Jump. It has a good collection of manga and ensures you're accessing the content legally. Keep in mind that subscription models and content offerings can change over time.
Some popular and considered safe yaoi manga sites include MangaDex and Webtoon. However, always be cautious when accessing such sites and make sure your device has updated security software.
Some popular hentai manga sites include Mangahere and HentaiFox. But be careful, as accessing such content may not be legal or appropriate in many places.