Yeah it s true the one who s checking in has to pay. You have two options. One you can call and ask if you can pay in cash then that way your friend might be able to check you in., or two you can try motel 6, and other small hotels around. Usually they don t care and they let 18 + check in or even accept cash. Good luck.
Your friend cannot check you in. Only the person who is paying can check you in. You cannotuse your mother s credit card unless she has designated you as an authorized user in which case you would have your own card. Your only option is to bring cash and register under your own name. If you are over 18 you should have little problem although you may have to show proof. Also without a credit card you probably will be asked to post a security in case of room damage.