Firstly, welcome to GEH
1. Local search is meant only to search the area you are looking at, so theres nothing you can really do about that except zoom out till you can see most of the USA & try again.
2. Go to the add menu, and select "new placemark" it will then let you name it, move it around and generally "edit" it, it will then put it in that MyPlaces list on the left ...To export/save them, i.e; to upload them here right-click the placemark and select 'save as', then save it to your desktop and you are set to go
Hope this helped!