Elizabeth, I am a hobbyist and not an expert, but I had a thought or two about this thread that might be worth your consideration.
In your post you wrote, "Wondering if anyone knows if there are any online archives which record what was happening to Company F,26th Infantry(Yankee Divison?)Army on 2 April 1943 in Tunsia?" This suggests that you had gotten Company F, 26th Infantry from some source, but were guessing the parenthetical "Yankee Division" with a question mark.
When the Army refers to an "Infantry", such as the 26th Infantry, they are not referring to the 26th Infantry Division but, rather, to the 26th Infantry Regiment. (A parallel is that when the Marine Corps refers to the 5th Marines they mean the 5th Marine Regiment, not the 5th Marine Division.)
The 26th Infantry was one of the infantry regiments in the 1st Infantry Divsion (F Company would have been in the Regiment's 2nd Battalion), and that division did serve in North Africa.
If it turns out to be the case that you are, indeed, seeking info on the 26th Infantry rather than the 26th Infantry Division, a quick search of the web found some info that might be of interest to you:
You may be able to get a personnel record through the NPRC in St. Louis. (They had a disastrous fire in 1973 which destroyed many records, but it is worth a try.) Info on that resource can be found at this web page: http://www.archives.gov/st-louis/military-personnel/index.htmlhttp://www.archives.gov/st-louis/military-personnel/index.html
I'm afraid I can't help you with the question about the enlistment record.