The first is simple: buying a ready-made (out-of-the-box) solution. In this day and age, it is likely to be a cloud-based SaaS LMS that charges monthly/quarterly/yearly payments for use.
The second is customizing an open-source solution to fit your needs. For example, certain features like game-based learning are almost never included in boxed systems. But you can hire a team to modify the existing LMS for this purpose. Note that “open-source” does not necessarily mean free. It just means that the code of the system is available for viewing and changing.
The third one is building the LMS entirely from scratch. Together with the chosen contractor you will plan out and implement a unique solution tailored to your organization’s processes and needs.