Oh I haven't used that function in years but there's a lot of helpful guides on it out there like this one. It's a little "complicated" for modern days but it works pretty reliable.
Funny enough streaming videos is vlcs "Main" function - VideoLanClient
No, it was invented to stream video files, I don't think it's able screen share, but you can use it easily for watch parties. Thats how I understood OPs question.