Since your profile says you have tested with both Ancestry and 23&me, your details are already in the system.
If you wish to upload your Raw DNA data to Wikitree, the answer is NO SORRY you cannot do that.
You do not really need to upload a GEDcom since you already have your tree in place, and you are already connected to the global tree.
Uploading a Gedcom is just making extra unecessary work for yourself.
In terms of finding more family members that will only happen when they join wikitree and add their families. But if they are not on wikitree, then there is not much else you can do. Sorry.
If your unknown family members are NOT looking (not adding family trees online and not doing DNA tests), then again, there is nothing else you can do.