Dear student,

You can get you college admission no. on your ID card and the online student portal of the college or university.

If you don not have the ID or portal service you can ask the college administration for the admission number and the transfer certificate number, you just have to write an application to the college administration telling you problem and the information you want form them and you have all the right to know the details as they are your and college can not deny your request.

For, the joining of first day of college date you can look for it in the college fees receipt (very first one) as the date mentioned there will be the date on which you are enrolled in the college.

Hope you find this helpful!