Salaam 3laykum ya akhi !
Our beloved religion did not begin with annabi Muhammad [SAW] but rather it was perfected in his time under his khalifah.
Islam began with annabi Adam [SAW].
Annabi Ibrahim [SAW] had a following of Muslims that was numerous and they traveled and settled in regions via his travels.
The people of the Sinai who assisted nabi Musa [SAW] were Muslims.
Just a few example akhi.
salaam, thanks to remind me. i missed to edit that part