The goals of this clinical study are to learn more about the study drug lenacapavir (LEN), by comparing the consistent and continuous use of LEN and emtricitabine/tenofovir disoproxil fumarate (coformulated; Truvada®) (F/TDF), then by observing the safety of LEN and F/TDF, evaluating the acceptability of LEN injections and oral F/TDF, and observe how LEN moves throughout the body in people who would benefit from pre-exposure prophylaxis (PrEP). The primary objective of this study is to compare LEN and F/TDF consistent and continuous use among people who would benefit from PrEP.