Hi there,

hope you are doing good.

First of all do not panic, everything is ok.

OPTION 1. open your email inbox and search NTA/NEET would find a email from NTA itself with an attached pdf file download it, that must be either your NEET admit card or your application form.

OPTION 2. 99% you will get your all details from method first, still if you are not able to get you aplication form or admit card, go to https://ntaneet.nic.in/ntaneet/online/CandidateLogin.aspx and click on " FORGET APPLICATION NUMBER". from further procedures you can get your details easily.

OPTION 3. If still you not able to get your login details email your problem  to NTA's official email id neet@nta.ac.in, they will shurely help you out with this.

hope this answer helps you.