Hi Glenn,
Your Gedcom can be downloaded to your computer then uploaded to WiKi. Here is a how-to section
https://www.wikitree.com/wiki/Category:GEDCOMs
You may find, as I did that the tree you have may be to large to add onto WiKi without going through many duplicates that may be here already. As this is one Tree and there are no duplicates.
You will have to go through and make sure your family is not already on here. It can be daunting at first.
I added my closest relatives and joined into the family further generations away that were already here. Then added spouses, children etc.
Welcome to WiKi, Happy Researching,
Lori