Any tips for making an experimental film?

I’m about to make an experimental documentary that I’d loosely describe as “a collage of borrowed memories”, wherein i won’t need a shoot but would rather just make sense of clips I already have, archival footage, and sound to create a film about the nature of our memories, loneliness, and growing up feeling like nothing’s ever really yours, from the room you live in to the words you utter. I’m making this as a personal love letter to myself and to submit to an alternative film festival. Also I’ve decided that I’d make these types of films as they don’t require a crew or expensive equipment, both of which I don’t have at the moment. I want this to be the best as possible and enter film festivals and make connections with filmmakers. However I’m starting clueless, besides the passion for my concept. I’m asking questions like: what editing platform suits this film, what is the best way to approach this, and the technicalities of editing and sound design.