Go checkout Paradise (https://www.nps.gov/mora/planyourvisit/paradise.htm) first! Lots of trails directly adjacent to the parking area, ranging from quick and easy all the way to days long affairs.

Once you've seen and hiked up to the glacier from there, I would highly recommend a stop at Comet Falls! (https://www.wta.org/go-hiking/hikes/comet-falls) You can walk/sit under the falls and look up at the 100s of feet of water coming down at you, really fun!