If I want to install Agda do I have to be attentive to versions, breaking changes, etc.?
A comment from an earlier question noted
Agda version for installed libraries
The breaking changes mentioned in my other answer is unlikely to get new users into trouble. However, you need to beware of the libraries you installed. A library is likely to use Agda features extensively, and breaking changes may more or less affect them.
For instance, the standard library usually releases with a specified version of Agda (similarly for the cubical library and the categories library). So, if you have installed Agda, remember the version and download the suitable version of the libraries. OTOH, if you intend to use a certain library, make you install the suitable version of Agda. For example, the compiler of Cedille does not work with latest Agda (see my pull request. I guess cedille devs don't care about Agda version at all), so you need to install the old version written in the build script.