I started cooking sous vide when my oven crapped out the week I was supposed to cook my Christmas Eve rolled beef tenderloin for my extended family of inlaws. I put it in a turkey brining bag and ghetto sous vide the roast in an ice chest — searing it with a blowtorch. Wonderful roast and a fun story.
I discovered the ANOVA device (I actually have two) over two years ago. I love it and have turned on a bunch of my cooking friends to sous vide with that unit (I let them borrow one of mine and then they get hooked.) I believe ANOVA is a lab equipment company that developed their ‘stick’ when they saw the culinary demand for their lab gear.
I’ve done chicken, pork, steak, and roasts. If it is something simple like steaks or chicken breasts you can just use ziplock freezer bags, submerge with the top out of the water to squeeze the air out of the bag, and binder clip the top of the bag over the side of your pot. You can pat dry and sear right after sous vide or chill the protein in an ice water bath and pop in the fridge. I’ll do up a whole tray of Costco organic chix breasts with various seasonings in different bags and then have chicken all week for chicken bowls, chicken salad, or quick seared chicken. NEVER overcooked.
A good site for info is serious eats:
https://www.seriouseats.com/sous-vide-101