Some courses are given annually, some every two years, but there are also additional courses which are given only occasionally or only once. The best source of information for future (and past) courses is the Course Management system (Modulverwaltung) of the department.
https://kvv.imp.fu-berlin.de/index_en.html → item 1: Course Management (no login required) → Planning/Planung → Longtermschedule/Langfristplanung → Faculty: Mathematics and Computer Science → Department/Fachrichtung: Mathematics / Bioinformatics / Computer Science
By clicking on courses, you can find information about the contents, in German and mostly also in English.
The information about the credit points is unfortunately not so straightforward to find. In the long-term planning view, you can switch between the Course-based view and the Module-oriented view.
In the module-oriented view, you have to select the appropriate study program (Bachelor/Master) as follows:
You then see the ECTS credit points in the left column in blue color as "LP".
In the course-based view: The leftmost column under the heading "Modules" shows one or several "module keys". Select the key with the prefix of your study program according to the above list and click it. A subwindow will open, and at the bottom you will find the ECTS credits under the heading "LP".
As a rule, classes with 4+2 hours (4 hours lectures and 2 hours exercises) typically have 10 ECTS, sometimes less, classes with 2+2 hours or seminars with 2 hours have typically 5 ECTS.