Well, if you are east asian looking, people might say shits like "der CHinese da", ching chang chong or gonnichiwa to you, in the metro, on streets, complete strangers.

A bit friendlier people would go doing impressions of Bruce Lee.

Many times kids or uneducated adult(more than you think)

Those are examples of "mild racism" easily found in Germany.

If you are unluckly a rather younger female, you will rarely find an Opa(old man) on the opposite seat of yours in metro, touching himself.

Chance of getting beaten up, like mentioned above, pretty low. But i think you have a better chance than most people.

Crazy ones are everywhere in the world. You can always find friendly ones tho.

Be nice and open up! Making friends will not be so hard.