How far can you go on single player?

I purchased this game so I could have a distraction and just simply destress from the real world but lately it is just causing me more stress lol.

I just reached lvl 15 and have not been wanting to play because I feel and know there’s no way I can run the restaurant and the drive thru on my own. No option to hire a cook. And I know I can close the drive thru but I feel as though the higher I go in lvls the less I’ll be able to maintain the restaurant