Top mirrorless camera recommendations under $500 for beginner photographers?

Honestly, the Sony Alpha a6000 with 16-50mm Lens is still a beast. But yeah, that battery life is legit scary for a Zion trip... I would suggest grabbing it used but make sure to budget for at least three spare batteries. Or look for a Canon EOS M50 Mark II with 15-45mm Lens used. Just be careful tho, Canon pretty much abandoned that EF-M mount recently.

Jumping in here to summarize what we've got so far. You're basically choosing between the Sony Alpha a6000 with 16-50mm Lens for its sensor size and autofocus or something like the Olympus OM-D E-M10 Mark III 16MP Mirrorless for that sweet stabilization. Both have pros, but like the others said, that Sony battery is gonna die on you halfway up Angel's Landing if you aren't careful. If you're still worried about the sensor size on the Lumix G7, you might want to consider a used Fujifilm X-T100 Mirrorless Camera. The colors are honestly incredible for those red rocks in Zion, and it has an APS-C sensor like the Sony. Just a warning tho, the autofocus isn't exactly snappy. Another solid shout is the Panasonic Lumix DMC-GX85 with 12-32mm Lens... it's super compact for hiking and the built-in stabilization helps a lot with handheld shots. Budgeting for the trip itself is key, so dont blow every cent on the body. You'll need a decent SD card like the SanDisk Extreme Pro 128GB SDXC UHS-I Card and maybe a bag. Buying from sites like MPB or KEH is usually safer than random sellers on eBay since they actually grade the gear and offer returns. Just make sure to check the sensor for dust and the lens for scratches as soon as it arrives. Gear at this price point is always a compromise, so just pick one and start practicing before June hits.

To add to the point above: I would suggest a used Olympus OM-D E-M10 Mark III 16MP Mirrorless instead. Be careful with old gear tho... but the stabilization is a lifesaver for shaky beginners.