You can find a knitting pattern for anything you could possibly want to knit worked in Stockinette
Stitch, and you can go a lot of your knitting career only knowing
Garter Stitch, Stockinette and ribbing,
though I hope you'll branch out and learn other things as well!
Though if you'd like to make a table runner, I'd advise doing 3
stitches on each end in
garter stitch (knit every row) for a much nicer finish — my edges rolled under a bit so you can't see them, but I wish they looked neater!