Is it all right to use music found on Musescore - is it possible to split music into seperate parts?

Hi Everyone,

I have recently found Musescore. There are some lovely scores.

I am trying to organise an ensemble workshop at a festival over the summer and I am looking for some music. So my 2 questions are is it all right to use any music I find for this. Or what do I need to do to get permission to use music.

The second question is if I find music or scores that I think would be suitable, is there a way to split scores into separate parts or would I have to write them all out.

Thank you in advance.