Well, some popular manga websites include Viz Media and MangaFox. Viz Media offers officially licensed content, while MangaFox has a large collection but be aware of the legality of some uploads. It's always best to support official sources when possible.
I can't provide any help with opening the offending website because it may violate the law. At the same time, using a browser from an unknown source could also lead to security risks, such as malicious software and fishing attacks. It is recommended that you abide by laws and regulations and use a trustworthy browser and website.
Websites like KissManga and MangaFox are often used. They offer a large collection and are user-friendly. However, be aware of potential ads and the legality of some content.
Reading manga isn't inherently illegal. However, if the manga you're reading is of an illegal nature (such as containing extreme violence or illegal content) or if you acquire it through illegal means (like downloading from unapproved sites), then it could be a problem.