2003 Other Dodge Models warning lights coming onand RPM's dr

Engine Performance problem
2003 Other Dodge Models 4 cyl Two Wheel Drive Automatic 95000 kilometers

I own a 2003 Dodge sx 2.0 and when we start off from a light or intersection a trouble light that looks like an exclamation point comes on for about 5-10 seconds. What does that mean?

Also the RPM gauge shoots up and down when idling, that isn't always happen, but it does happen frequently. It starts at say 1000rpm's then drops down to about 400rpms then shoots back up to 1200rpms then levels out to about 500rpms after doing tha ta couple of times.