If you want a super easy blanket that doesn’t require a pattern (like you can talk, watch TV, etc., while you do it), you can do a simple basket weave.
K4 P4 repeat across. Knit the knit stitches and purl the purl stitches for 3 more rows. Then P4 K4 repeat across. Knit the knit stitches and purl the purl stitches for 3 more rows. Repeat pattern until the blanket is done.
So every 4 rows you’re changing the knits to purls and it (kind of) looks like a basket weave.
I just finished one. I have an acquaintance who is a chaplain at a local hospital who gives out blankets to preemies in the neonatal intensive care unit.