I have a 1999 Ford Ranger that idles good after you start it and it runs for a second it starts running good when you put it in gear it starts bogging out and won't hardly pull itself once you get going if you just barely give it throttle it will smooth out but if you go either way with a throttle it will start cutting out bad

 

Welcome to the forum

Assuming 3.0l engine from your user name?
Manual or automatic?

Not much to go on
Change Fuel Filter, check fuel pressure, expected with engine running is 60psi

Clean MAF sensor
Make sure air cleaner is not clogged up

If you have a vacuum gauge you can test if exhaust is clogged up