joined
v.v. to become a member of a group or to connect two things together. You use this when you start doing an activity with other people.
v. to become a member of an organization or group; to connect or fasten two or more things together. Transitive when taking an object, but also used intransitively to describe the act of becoming a participant.
She joined the local gym to stay healthy.
After moving to the new city, he joined a book club to meet people who shared his interests.
The two major railway lines are joined at the central hub, allowing passengers to transfer between regional and national services without leaving the station.
The verb is often followed by a direct object representing the group or organization.
He joined to the clubHe joined the clubThe verb 'join' is transitive and does not require the preposition 'to' when referring to entering a group.