The backpack is a better idea.
Found one on eBay, and I really like it.
It’s light, carries a lot, and sells for $22.99 on sale.
It’s out of stock often, but when it becomes available again, it’s $22.99 instead of upwards of $45-$80.
Right now I have the following in it:
Laptop
iPad Mini
USB charger 15,000 rating two ports
Laptop charger
Various connector cables, so I can recharge my own and my friends cell phones
Wallet
Three sets of Keys
iPhone X
Tic Tacs
Chapstick
Towel for wiping screens clean