Frankfurt Airport

Strausberg near Berlin?

Train to Berlin, and then a short connecting local or regional train to Strausberg. Too far for a bus in my opinion, but Flixbus is an option if you're travelling on a budget.

If you are referring to Strasbourg, France, take the train.

The train from that airport is extremely convenient to access and it would be both my choice and also recommendation.
I am not a big fan of Frankfurt so when I arrive there, I always rent a car or take the train outside the area to spend that first night. Instead of thinking about it being too early to check in somewhere and wondering what to do for those few ours, I move along. It works well for me. I arrive elsewhere around check-in time hungry and ready for a nice pils.

By Berlin? Fly. In France? Train.

In this case spelling really makes a difference.