Living cost and job

As a non-EU citizen, in order to get a work permit in Germany, you need to have skills that cannot be found among EU citizens (who otherwise have to be preferentially hired). The authorities have published a list of professions (available on the Internet - google it! - but only in German) where this is the case. If you are not in one of them, your chances are low. (And "whatever job" will not work - there are many unemployed Europeans who can be housekeepers or "whatever".)
In additione, you have even lower chance of finding a job (at least one with reasona
ble pay) without German language skills, so you might want to learn that first.
Regarding your original question about living €800-1000/month is usually sufficient for a simple lifestyle, but as a new arrival who doesn't know yet how to get things done cheaply you should budget 50-100% more for the first months.