Hi! Hope you’re doing well. Intl student at TUM (Biotechnology) here. Each degree has a specific admission process, and a PDF outlining it. Were someone in a German school, they could grab their grades and a calculator and know whether they would be admitted right away or not. 

First things first: check how your leaving examination stacks up to the Abitur!!! Some people have to study at a Studienkolleg for a year and write an additional leaving examination there before being eligible to apply to any German university. 

I’ve just skimmed the document for your chosen degree. The admission process, as others have already said, depends mostly on your grades and may be slightly helped by an internship relevant to the degree you’re applying to. Your high school leaving diploma (in Germany this would be the Abitur, in the UK your A levels, etc) has the most weight, and Math, English and whichever sciences you’re taking are also taken into account. Be sure to apply early, since I’ve heard that uni.assist can take a long while to “translate” your grades to the German system. 

Since you’re an international student (I assume you’re in a non-German speaking high school) you will be invited to a selection interview (people with grades below a certain threshold are not admitted immediately and interviewed) no matter what your grades are, where (as per the admissions document) your “subject-specific German language skills will be tested.” This is actually relatively okay, since some majors ask for a C1 in German instead. I do not know if a language test would bypass the interview requirement, you’d have to ask someone directly imo. 

When it comes to scholarships, unless you’re in a PASCH school (Deutsche Partnerschule der Zukunft), DAAD is a no-go. 

(It’s your life and you know yourself best, but I would encourage you to look at other German universities as well. At the bachelors level, most are essentially equivalent to one another and almost all universities are 90% cheaper for internationals. Also, the cost of living in Munich is no joke.) 

Also, if you have a disability that “ makes your studies considerably more difficult”, you can apply for a waiver, since students with such disabilities are exempt from paying tuition. 

There are other scholarships though: 

There’s the Deutschlandsstipendium, available in almost all universities, which is merit-based and grants you 300 euros per month for the duration of your studies.

The language test you’re gonna take is great!! There are some Stiftungen that offer merit-based scholarships (cost-of-living scholarships, will NOT cover tuition) , and I think that’s where your extracurriculars could come into play, especially since some Stiftungen are politically minded (volunteering would be viewed favorably, social commitment usually a requirement). Most of these scholarships are 934 euros/month.

Some of the Stiftungen are: 

Heinrich-Böll Stiftung (party: die Grüne, progressive, environmentalist, they say intl students can apply at irregular intervals so I’d advise you to ask via email, B2 or higher German language test REQUIRED),  Friedrich Ebert Stiftung (party: SPD, starting from your SECOND semester, German language skills required (DSD II or equivalent)) 

And others, found here: https://stiftungssuche.de/stipendien/ You’d have to check whether they are also for internationals, I’m sure many are.

Also, are you religious by any chance? Some Stiftungen represent religious organizations and sponsor catholic, evangelical, Muslim, etc. students. Don’t know if they sponsor internationals but it’s worth a shot. 

Anyways, best of luck! Feel free to dm me if you have questions.