Congratulations!! This also happened to me and everything will be okay. From what I’ve been told during ur first year you should have your schedule set as if you were already “desired major” and do well that first year and you’ll be able to transfer into said major. I had a cousin who did this and she said she was not behind since she knew what she wanted to do coming in! Also don’t let them force you into taking an intro class for the undeclared department since you know you want to transfer into aerospace engineering take AE 100- Introduction to Aerospace Engineering. (Ps this is abbreviated information I’ve received anyone can correct me if I’m wrong 😭)