For a detailed walkthrough of setting up SciENcv for the first time, click Home above.
Once you have a SciENcv account, choose the +Create new document link, pictured here. It's in fairly small print so it may be hard to spot on your SciENcv page.

That will take you to a page where you can choose what kind of document you want to create: NSF biosketch, NIH biosketch, NIH fellowship biosketch, IES (Dept of Ed) biosketch, or Current and Pending (Other) Support for either funder.

Choose the source of any reused data that you want to import, such as reusing a previous Biosketch or CPOS page or importing education and employment information from eRA Commons, Research.gov, or ORCID. You can only choose one source for data at this stage, so choose the one that will have the most and most accurate information to serve as the basis of your new Biosketch.