How low does the bike have to be in order to drive safely? (too small -.-)

Hello, I finally decided to make the A1 driver’s license. I wanted to buy an Enduro so much and looked at some models on the internet. My driving instructor then brought me to the hard ground of reality… For an Enduro I am much too small. I am a girl, not very heavy and only 1.65 m small. In the driving school I drive a chopper. I want to drive something like this later on GAR NO FALL. Also an athlete comes for me rather not I would like to have something in the direction of Enduro… Now I looked at the supermotos, which are a bit deeper than the enduros through the tires. At a dealer nearby I sat down on the Sachs ZZ and was thrilled by it. Even the price (3,200 euros) would be somehow possible. There was only this one problem again: sitting height 83 cm… I came to the ground with the toes and could keep the motorcycle in free standing. Also the descent fun The dealer immediately said that it fits everything and wanted to sell it to me immediately… It would even be possible to put the spring down and reduce the height a little bit. I was totally happy about it but the disillusionment came soon. Both my instructor and several acquaintances who ride the bike say that you MUST stand on the ground as a beginner with the complete foot, because otherwise you will tip the bike. i traffic lights etc. Now I don’t know what to do anymore. I really want to drive the Sachs ZZ, it’s even close to the price budget, but I’m afraid that I won’t be able to tame it later, fall over or something. You could put it through the lower spring, loosen the spring and possibly lower the cushioning of the seat, but is that enough? I’ll probably never be able to get up with the whole foot. At the moment (83 cm sitting height) I’m just standing up How far can the Sachs ZZ be made deeper? As a beginner you have to get up on the floor with the complete foot or rich toe tips? Are there lower alternatives for the Sachs ZZ (not more expensive than 2,500 euros!!!) Thank you Achja: This is the Sachs ZZ: http://www.sfm-bikes.de/bike.php?bike_id=363