22 and weight 240 pds & have a 2year old

Before I was pregnant I weight 195 at 19 and was actually gonna start losing weight then. After I had my baby I weigh 212 then I gained weight the pass 2 years. I need advice on where should I start . I’m 5’5 and I want to lose 70 pounds is that possible to do in a year? I tried a lot of things and they didn’t stick . I need advice please help!