I do not have any form of I.D. other than my school I.D. Can I just register online and print out the electronic postcard as proof that I am who I say I am? Or would I be better off doing at-con registration?
You can always work something out with registration by emailing them at registrationATfanimeDOTcom (Changing the "AT" and "DOT" to @ and . of course). I was in a similar situation last year and was able to work something out. They're very helpful. :)
Do you have a parent with the same last name who would be willing to stand in line with you then leave after you have your badge? They might be willing to use his/her ID in combination with your school ID as proof of your identity. You should also print out the electronic postcard and any email conversation you have with them so you can prove that you had the conversation.
yes, please email registration.