I am a very casual yoga practitioner...in my living room with my computer screen, which has no judgmental eyes. I think it definitely helps me reduce stress, helps me sleep (I've experimented enough to realize this was true), and helps me keep the muscles in my neck, shoulders and back from locking up post injury. I've never set foot in a yoga class. I might one day. I'm sticking to my living room where I have practiced (on and off) for 10 years. I could talk for an hour about how much yoga helps me.
If you're worried about getting into those "stereotypical yoga shapes" that you see in pictures, do yourself a favor and don't think like that. Do the best you are able. Don't worry about getting a "perfect" shape for the stretch. Start with the objective of being in the moment, breathing and stretching your muscles. Yoga should always be a positive experience.
Just find one or two beginners yoga videos on YouTube and alternate between them for a couple weeks, if that's what you want to do. You can literally search "yoga for beginners". My favorites are Yoga with Adriene and YogaTX (pay attention to video titles with this channel). They have whole playlists dedicated to beginners yoga with a variety of video lengths from 15-40+ minutes. The instructors on both of those channels also give you modifications to the poses if you can't stretch like a Yogi--I still can't. They also won't talk down to you. They are very positive. I have to use many of the modifications because of body type and ability level. But, do what is comfortable for you. I only know what has worked for me.