I was wondering if there is a website I can use to download and import families or cell into the project.
OpenBuildings CONNECT Edition Update 13 integrates with Bentley's ProjectWise Components Center service via the Components Center Explorer and Components Center Upload dialogs.Components Center is a cloud-based digital component library and catalog management service. It allows you to efficiently manage your organization’s digital component repositories while providing you with industry approved, proprietary components. The geometry and business data associated with the components is available for use in all phases of the asset’s lifecycle.
To access that from OpenBuildings Designer You need to be in the Building Design Workflow and under the Architecture ribbon, there is an drop down under Objects which is called Place cell from Components center. There you will find readily available cells.
Also you can get cells/families from DWG, RFA, STEP,JT,Skp and any more from the import dialog. The import dialog can be access from File -> Import.