Verb conjugation of "verhalten" in German

My brother moved there last year. He met a woman and went after her. After six years they have broken up, but he no longer wanted to return, because he has settled down in his new home. I am visiting him once a year.
In order to quickly become successful, one would have to change certain points, at least in my opinion: After 5 months of learning, I have still not found the grammar practice on which I should concentrate.
You need to call before you leave... When there is good weather outside all restaurants open outside and the people sit in the sun, eat and drink. The lake is also very romantic in the late night.