An easy way to contribute to the PsychoPy project is to provide translations so that other speakers of your language(s) can more easily use the software.
If you’d like to contribute in this way, register your interest here. It should only take you about one or two minutes.
The only pre-requisites to translating are a native (or near-native) knowledge of the language you want to translate into, along with at least a moderate understanding of PsychoPy. We will help you with everything else (e.g., git, GitHub, Poedit) through online workshops.