This study is researching experimental drugs called trevogrumab and garetosmab (called "study drugs") in combination with another drug, semaglutide (Wegovy®). This study will be done in 3 parts, Part A, Part B, and Part C where different study drugs will be tested. Part A of the study is focused on healthy participants. Part B and C of the study is focused on participants with obesity. The aim of Part A of the study is to see how safe and tolerable the study drug is in healthy participants. The aim of Part B and Part C of the study is to see how safe and effective the study drug is when combined with Wegovy. Parts A, B, and C of the study are looking at several other research questions, including: * What side effects may happen from taking the study drug * How much study drug is in the blood at different times * Whether the body makes antibodies against the study drug (which could make the drug less effective or could lead to side effects)