Hi, I was in a very similar position of not knowing what to do and how. I found that just by cutting out all junk food, processed food amd all sodas I started losing weight. That combined with some exercise has worked well for me. Whatever you do, make sure it manageable, start off slow and buid it up.
I found that starting a diary on here really has helped me, not just with food and exercise but also random other stuff like how I feel is related to what i eat/do! Give it a go.
There's loadsa friendly people on here if you want help and support!
Good Luck