If you mean that your father recently got a job, you can say "My father started working" or "My father started to work". If you say "My father starts work" it usually refers to starting at a specific time, such as "My father starts work at 9" I hope this helps :)

If your father just started (began) a new job: My father has started working. My father has started working again. If he got the new job but didn't start it yet: My father starts his new job on Monday. My father will start his new job on Monday. My father will start working again on Monday. Hope this helps! :)

My father starts working at 8pm. My father starts to work at 8pm.