Weight loss help!

Okay so I'm really not okay with how I look and how big I am, I have stretch marks EVERYWHERE which really doesn't help with my body confidence either..and I am extremely unfit... I'm a size 10 (in uk) in shirts and tops and a size 12 in trousers (pants) and I'm really not happy with it, all my friends are size 4 and completely love themselves.. I'm putting this up on here to see if anyone could give me advise or tell me stories about what they've done to lose weight.. I'm starting to eat healthy and go walking everyday but can anyone help me with other ways? I really need some help guys 😪