First car for 7000 euros?

Moin Moin, after having already opened the thread in the Opel Astra H Forum, I thought it would be more logical to ask here as well. Now I am 17 years old, towards the beginning of December I will be 18 and need a car, for work, etc. One can say to me that I already have a little driving experience since I used to go professional karting (and I know racing is uneven road traffic). Also I have now driven a little accompanying (BF 17). What do I have for Anforderun gen? – Budget: up to approx.700€, if I like something very much also not more. – The car should have a sixth gear, for various motorway rides – My car should also not have too little power, since I plan the car already for a few years.. of course not too much power – A mileage of max. 70,000? 60,000? The car should certainly not cause me any problems in the next time. I have heard that the mileage of small cars is not too big should.. – Dear quality as quantity. But I have never had a car of my own, which is why I can’t answer anything on sentences like “Get a German car, they’re good” .. – Finally I would be happy about a five-door.. but it won’t be a three-doorr either. I think that was it for the first.. I would be happy about some nice answers! Thank you already in advance..