There are several professions that civilians can choose. Professions give you a bonus to skill gain and could give you access to producers or processors.
In most cases you need a specific skill level to get a profession. Changing professions costs 50.000$ and there is a 24 hour cooldown after changing.
Civilian Professions
Miner
You can become a miner at the quarry if you have reached mining level 3. Active miners with mining level 5 also can use the mining quarry.
As miner you get a boni on gaining mining experience.
Blacksmith
You can become a blacksmith at the forge if you have reached smelting level 3. Active blacksmiths with smelting level 5 also can use the furnace at the forge.
As blacksmith you get a boni on gaining smelting experience.
Beekeeper
You can become a beekeeper at the beekeeping if you have reached honey spinning level 3. Active beekeepers with honey spinning level 5 also can use the honey extractor at the beekeeping.
As beekeeper you get a boni on gaining honey spinning experience.
Carpenter
You can become a carpenter at the carpentry if you have reached carpentering level 3. Active carpenters with carpentering level 5 also can use the honey extractor at the carpentry.
As carpenter you get a boni on gaining carpentering experience.
Refinery worker
You can become a refinery worker at the oil refinery if you have reached oil refining level 3. Active refinery workers with oil refining level 5 also can use the machines at the oil refinery.
As refinery worker you get a boni on gaining oil refining experience.
Parcel carrier
You can become a parcel carrier at every parcel station if you have reached parcel delivering level 3. Active parcel carriers with level 5 have a chance to get express parcels that have to be delivered in a specific time, but give you more money.
As parcel carrierr you get a boni on gaining delivering experience.