Finding good legal templates can be quite difficult, since they often need to be very personalized. That is why it is for most of the legal documents the best, if you search for multiple similar templates, and then create your own document based on the templates and your needs. Besides the resources below, Google or old documents you received yourself can be quite helpful.
The documents are published on a open source base. That means, that they may NOT be legally binding. Here you can find all kinds of legal documents for free.
Here are free internship contract templates in English.
Here is a free internship contract template in German
This employment contract template is written in English written for the laws of Germany
This legal text generator is completely in German, but creates legal texts for online shops in eight different languages