1991 Ford F-150 1991 F-150 problem 240,000 miles

I have a 1991 Ford F150 4.9 manual 2wd. 240,000 mi
She has been running great until recently. A couple months ago she began to idle very high when I started her up. About two weeks ago she began to have a hard time starting at all. She fires but I got to give it some gas to keep it going. Mostly in 3-4 gear at high RPM's if I’m giving her some gas to pass a truck or something she sputters as if she’s missing. From what I’ve heard it's most likely fuel injectors. I've only been driven it for a year and my dad does not remember the last time he changed the plugs(been a long time and I have no idea how many miles). By the way I’m truck stupid at the moment and still learning. I hope/think this is a stupid and simple question and all input is greatly appreciated.