How do i block an aggressive and rude person on this site?

You can't block someone from posting on this site or on your posts. However, if you think the comment violates WW's guidelines, then you can flag it. If the mods agree, they will remove the comment. If that particular person has been flagged so many times or if the mods view their conduct as offensive then the mods will ban them.

However, keep in mind that being direct and/or matter of fact is not rude or aggressive. A lot of users, especially more experienced users, don't sugar coat their advice. That doesn't make them rude. Often times what someone finds as rude, others find as refreshing and to the point.

Earias is correct. There is not a way to block any members on the forums. However, if their posts are violating the Community Guidelines, please flag them for review.