Should I make my code and data avaiable online when the article is not accepted yet?
Ultimately, it's up to you. I do not really see a reason to keep your data and code private, but you may very well have a valid reason to do so. Hence, I cannot answer the question what you should do.

If I were in your position, I would do the following. I would include a link in the manuscript to the data and code, and write that at this link you make the data and code available for reviewing purposes. The reviewers can then access it all so that they can fairly review your paper, code, and data, but if they behave responsibly, none of it should leak to the wider world. I would add a footnote specifying that the code and data will be made available to the public upon paper acceptance.