'99 2.2 s10 rough and dirty

i need help with a truck ive had for a couple months. it starts hard, runs rough and getting worse. only 50k from power company fleet. also, oil pressure high and oil now covered with dust, all over engine and compartment.oil ps fluid and tranny fluid were all strange brown/golden color, had all changed, lee myles said had bad valve cover gasket. ive had several chevy four bangers, but this 99 looks so alien, i can hardly see the valve cover. took two hours to find first thread and i need help from your professional expertise.im guessing egr and or pcv plugged/clogged and hoses/passages but with hard start, very worried.almost sounds/feels as if engine is about to quit.in serious trouble. dont have much money, must fix with son.
first question- where to start
check engine light works, but is not on when running.many cars in family, i guess we're mechanics, but not really.
should i have codes and stored history read first, or can anyone suggest where to start with these problems. never been on forum before, so i apologize for short story, but we really need some serious professional guidance

thank you so much for your time, i hope this aint too much for y'all
please help.
p.s. engine vin s144 auto tranny.

sounds to me more like a blown intake gasket

Is your model the Vortec 2.2 or the L2.2. I am assuming with the foreign engine as you call it is going to be the Vortec. I personally have the 2.2 vortec 99' model. I found that by cleaning the throttle body very thoroughly it made a very distinct improvement. I had another problem to look out for at about 90,000-100,000 miles I had the Throttle Position Sensor go out and leading up to it the whole truck acted crappy as you are describing. What happened was the spring inside the sensor finally broke and the computer ran my engine from there. I am at 116,000 miles now on the truck, keep posting and I hope to give some good answers.

At the 70,000 mile mark my fuel pump went out and I had it replace. Put new shock absobers on at 80,000 needed it way before that though. Found the vortec is picky on its selection of spark plugs, stick with platinum ac delco plugs. Haven't had much else out of this truck yet.

I would try the IAC motor/valve a lot of times this sensor will cause bad starts and if you don't have a lot too put into this you can try to clean the pintle on the sensor. The sensor at AutoZone cost like 35 something dollars. Have fun.