My "Drive", "1st.", and "2nd" gears are no longer working but reverse still works. Any suggestions? What other vehicles transmission are compatible with mine. transmission

All you can really do is check fluid level and condition. If good, then it's either an electrical or internal mechanical concern. I'd lean towards mechanical, but testing is needed to determine that. It depends which transmission is in your Expedition -- A 4R100 or a 4R70W. Plus, which engine, a 4.6L or 5.4L V8. You might get lucky and find a 2002 F150 that is similar, but other than that, stick to the 2002 Expedition and maybe a year before and after. A good used parts source will have a good parts application list for this.