How would I go about starting an Film/ Art Portfolio ?

Answered

To start a film/art portfolio doesn't need to have just films in it. Scripts are also a great thing to put into a portfolio. If you do want to have films to put in now, I would suggest making a short film. You could just get a couple of people to be in it and then start recording it. It seems like you have many film ideas, so just make them into scripts and then maybe even into actual films. You are only a sophomore, so you don't need to have a huge portfolio just yet. You could also watch youtube videos or take classes that show how to make basic short films if you want to start. After this, I would then build off of this and then start making bigger, more professional things. Getting a job as an assistant for something related to film would be good. This would give you experience so that you could build a better portfolio. Don't worry about how professional it is now, just start by writing scripts and trying to make short films.