Random Merge Requests, Issues and Branches Appeared in Repository

I created a private repository about a week ago and yesterday I saw a bunch of erroneous/random merge requests and issues that have been created in the repository. The issues/merge requests say that it was created by me 3 months ago which makes no sense as the repository itself was created 5 days ago. It also has a bunch of random labels and milestones attached to it. I have deleted the repository for now but wanted to report it here. I have attached images for reference. Please advise what to do if it happens again. Thanks.