How can I find out who is accessing my Apple ID account?

You can't find out who the person is. There isn't a list that tracks who tries to access your Apple ID.

Check your device list to see if there is a device signed in that you don't recognize. You can remove the device using the steps in the article below. As a precaution, change your password.

Apple ID device list -Check to see where you‘re signed in.    

 Apple ID Password Change.      

 What to do after you change your Apple ID or password - Apple Support     I suggest doing this before you change your Apple ID or password.

You are welcome.