Hello and welcome!
There is no "best" med school in Germany because there are nationwide study regulations to be followed by all med schools. Choose your region according to rents, leisure time facilities, etc.
As a non-EU citizen you have to send your application directly to the universities (whereas Germans and other EU citizens use a centralised service which distributes the applicants to the different med schools according to certain criteria). There is a fee-based application service for international students that you can have a look at:
http://www.uni-assist.de/index_en.html
The
Goethe-Institut is the official language teaching institution but there are alternatives as well. Once you have reached a certain level of fluency (level B1
CEFR after approx. 400-600 lessons) you can try to be admitted to a
Studienkolleg for further university entrance preparations.
Good luck!