Help loosing weight

Hello, I’m 21 years old and getting married in a month! Just a few weeks after our wedding my fiancé is getting deployed. While he is gone I really want to focus on bettering myself and loosing weight. I currently have the nexplanon for birth control and am very seriously considering getting off of it during the time he is gone. Either way I would love any advice on if I should get it removed, if I do how do I get back on when he comes home? And also any advice and tips on loosing weight especially on birth control! TIA!