There are millions of VAs in the world who may not even be members of any forums. So, yes ofcourse you or anybody can become a VA. It is a personal career related choice based on one's interests & skills.
However, as a VA or a service provider, if you want to offer your services in BHW, then you need to be a Jr.VIP and follow the guidelines as to how to offer your services.
And about being able to work 24/7, it may not be physically and mentally possible, unless you have an additional person or people along with you (a team). Yes, there are automation tools available, but those looking for a VA are doing so because there is human work involved (otherwise they would use automation tools instead of hiring a VA). As a VA, even if you use automation tools for certain tasks, human interactions are needed and a single person is unable to work 24/7. So, whenever you are approached by a potential client anywhere, always be realistic (just a tip towards your success).
Wish you all the best for your internet marketing, internet earning journey.