Meta contributions have absolutely no effect on system-instituted question or answer bans on the main site.
The same applies for the inverse, as well - contributions on the main site have absolutely no effect on system-institutted question or answer bans on the Meta site.
Your question-ban is in place on the main site because a substantial portion of your asked questions were flagged as content that is poor, and/or were closed as offtopic or duplicates of other items, and/or were deleted. When a substantial portion of your questions are flagged and/or deleted by community voting and review queues, the system automatically institutes that block.
To get rid of the question-ban, you have to contribute positively to the main site in other methods, such as posting good answers and other positive activity. Once the system determines that you have enough positive contributions to outweigh the evils which led to the question ban being instituted, the system will automatically remove that block and you can then ask questions again. (This cannot be influenced by moderators or staff)
The system-instituted question and answer blocks operate indepdently of each other on a given main site and its corresponding Meta site. They have no impact on each other.
(Rule violation suspensions, on the other hand, affect both the main and Meta site, so if you get suspended by a moderator or a community manager for rule violations, or the system automatically as a result of some other thing behind the scenes, you're banned on both sites, and not just for posting questions and answers, but from doing anything except browsing site content and replying to moderator direct messages sent to you - in effect, read only mode.)
As for your other two questions:
Also, how much good do you have to do?
Is it measured in reputation or the number of people reached?
This information is not known to the public. It is an internal, secret, undisclosed algorithm that only the StackExchange software devs truly understand. We cannot measure the exact extent of what you have to do to resolve such a ban, as it can't be quantified without SE releasing that information (which they won't do).