what is if i live in the middle of a country and need at least two trains to leave it?

Hi everyone, 

My friend and I have a small problem and are wondering if you guys can help. 

We both live in the middle of Germany and therefore need to change trains in order to leave the country and to come back. Is that possible to change trains in our own country ? For example, we live in Halle Saale and we need to go to Munich before we can leave the country to Vienna is that even possible with Interrail? Can we use one of our travel days for that? Can someone please explain that to us? 

Thanks so much 

isa xx