Here are some helpful links regarding resources, you install peds like any other resource, in the stream folder.
[How-to] Install a FiveM resource / Script
[Tutorial] Merge Meta (Multiple Cars in 1 Resource)
[How-to] Add Car Parts from Add-on Vehicles to your server
Tutorial fiveM Resources , Add-ons , PED’s (Skins)
[How-to] Split Vehicle YTD Files to Avoid 16Mb Stream Limit
[How-to] Change the spawn name of a addon-vehicle