(2) And if someone has already earned some money from these jobs although he knew that it is haram, and after sometime if he left the job and wants to do taubah so what should he do with the money he earned from that job and already used?
بسم الله الرحمن الرحيم
(1) If all the work of gas station is of lottery and haram meat then it is not lawful to work there.
(2) Whatever money you have earned from unlawful employment whether they are available with you or spent, you calculate it and give that much amount to poor and needy ones without the intention of reward. If you are unable to pay it once then you may pay it in small instalments as well as keep on doing taubah and istighfar.
Allah knows Best!
Darul Uloom Deoband