
That is not so easy.
As far as I know a GEDCOM upload will not import any pictures and would create many duplicated profiles that should be merged. I would advice against that.
You could try uploading it to MyHeritage (or another site supported by SmartCopy [see https://www.geni.com/projects/SmartCopy/18783]) and then use SmartCopy to copy the on Geni missing parts from MyHeritage (or other by SmartCopy supported site) to Geni using SmartCopy.
Also keep in mind that it is not easy to keep your tree updated with new information from Geni. The Geni tree is big (see https://www.geni.com/worldfamilytree) so it is not easy to determine which info you would like to have in a local tree.