Question about oil.

I have a 1993 Saturn SL2. I bought a couple of quarts of oil today, but I've never bought oil before since this is my first car, so I had no clue what that SAE stuff meant until a few minutes ago. I bought 2 quarts of SAE 20W-50 oil, but when I looked under the hood, the oil cap said "SAE 5W-30 SG" on it. Which is better for my car, and will the SAE 20/50 oil still work just as well?

best not to use 20W-50, its pretty thick.
if you are in a warm area use 10W-30
if you are in a cold climite use 5W-30
also try to find a SL or SM service rating.(newest stuff, SG was top of the line in 93, but not anymore)

Use what the car manual suggests (5w30 fo 5w40) unless you
have a lot of oil usage....I had a 98 sl2 that used 2 quarts overy 1000
miles or less....I started using 20w50 and the usage dropped a lot...
but hopefully you will be ok with the recommended oil...G'Luck

I'd recommend the right oil too, unless you're using lots.
Then I'd try 10w-30 1st.
If you want to get rid of what you've got, find a friend who needs it, or use use a little (1/2 litre) per oil change