You can use Aurora Store to install apps from Google Play without Google Play
Not all apps may work though, Sapio is a community-ran project to keep track of which apps work well without Google Play Services
(You can, however, use LineageOS for microG to get LineageOS with the Open Source Google Play reimplementation microG or install Google Play Services on LineageOS with something like OpenGApps (which is an open source installer for the proprietary Google Play Services, so not truly open))