I asked a question, but it has been closed because it was considered not a good question for the site.
What can I do? Does closing my questions mean I am not welcome to ask questions?
When a question is closed, it means that in its current form the question is not a good question. It doesn't mean the question cannot be made better, and it will be never re-opened. Quite the opposite, the question can be edited to make it clear, or to make it a better suit for the site.
The question is immediately closed (as quick as possible) simply to avoid users answer a question that could be successively rewritten.
Closing a question doesn't mean "we don't like you, and we don't want you to ask questions here." A closing vote is never done against a user, but it is rather something done to control the quality of the questions; the message is "your question doesn't meet the quality standards we have, but you can make it better, and it can be re-opened."
If you can re-edit it to make it a better question, edit it. Once you do that, there is nothing else that you need to do, not even to flag the question for moderator attention (except in the case the question has been edited, but the edit was not sufficient, and the question required further edits).
In fact, once a question is closed, and it is edited, it is added to a review queue where other users can edit it, and vote to re-open it.