my service engine light came on and it blinks while I drive what does that mean on 1998 Chevrolet S10

this happened two days ago I turned my truck on and it started sounding really shaky and even to idle it takes time. I changed out spark plugs but still have that problem. I also did oil change

Asked by for the 1998 Chevrolet S10
that's a check engine light. you need to have it scanned
for codes to see what's wrong. some parts stores do it free; some shops will waive diagnotic charges if they do the repairs.