What’s in the diaper bag, crawling:
1 diaper for every 2 hours you’re out (also always error on the side of too many). If you’re cloth diapering bring an extra shower cap style cover in case of poo-plosions.
Extra pair of pants/ leggings. My son went through his oneises like lightening and I learned that a pair of leggings always worked great so I didn't have to change his shirt, just pants.
Bring all the toys; no, actually I discovered that a few lightweight toys were the key to a happy outing. Throw in the diaper bag three chewable toys, something that rattles and I love silicone big baking cups for a cheap toy that is food grade and easy for tiny hands to manipulate.
Pack the basics: corn starch, diaper wipes and diaper cream.
A portable changing pad is great for having to change at the park, beach or bathroom counter. Personally I’ve tried to edge off the cleanliness cliff by not spraying down the changing tables at every bathroom. Because as a single mom I just have to let some things slide but you can make your own changing table cleaner. Mix, in a small spray bottle, equal parts cider vinegar and water. You can mist it over the surfaces and then wipe down. If baby touches the cleaning solution it is pretty natural will not cause the reactions some cleaners do.
Be brave mommy, go out into the world with a well packed diaper bag and get out of the house.