PowerBI Fabric Question

Currently have PowerBI on-premise within our enterprise and looking to move to the cloud. Based upon our user base (5,000), it makes sense for us to purchase a reserved instance (F64) and a few power bi pro licenses for the developers. Our data source is on-premise, so we'll use a connector. My question is, do I need to also purchase cloud space to store any data with PowerBI, or would I be "good to go" with just purchasing the F64?