Halloween // First time attending costume party!

Heya... going to my very first Halloween party. Theme is UFO, Galaxy and all that. Since I've never done anything like that then I lack of inspo. In my eyes the costume should be neat and detailed as it can be (month to prep) but at the same time funny and give ppl the "what the fuck is that" first impression. Idk my mind thinks Men in black style but just suit would be dry in my opinion.