The biggest collection is https://pennsicdance.aands.org/pennsic47/Pile2018.pdf

Another large collection that is free for SCA musicians is at http://sca.uwaterloo.ca/sca/Hendricks/

If you want to play in Ansteorran dance bands, buy Al Cofrin’s book at https://www.istanpitta.com/…/book-early-period-popular…/

Other music to start with: http://www.twmarsh.net/music/2015/09/dance-consort-music/ and http://www.twmarsh.net/…/09/instrumental-consort-music/