You need to plan how to get home from the hospital. If you can't arrange for a friend to drive you, you have to look into medical taxi services. Most hospitals will not allow you to leave in a regular taxi, and so you would have to leave "Against Medical Advice" if you were planning on a regular taxi, which in turn affects what your insurance will cover for post-op complications. However, it is generally possibly to find a medical transport that is actually cheaper than a taxi. Maryland Department of Health maintains a list of Non-Emergency Medical Transportation providers, as does the New York Department of Health.
Check to see if your insurance will cover you to stay overnight in the hospital after surgery, or see how much it will cost out of pocket if insurance is not covering the surgery. The first night is the most difficult and it can be useful to have nurses responsible for your care if you cannot have a friend take care of you at home. A cheaper out of pocket option would be to hire a night nurse or home aide for the first night (or longer if you can afford it).
Know signs of post-surgical complications like infection, blood clots etc. and who to call if issues arise. Ask your doctor to write these down for you if they have specific concerns. Don't try to tough it out alone.
Post-op, you have to plan a recovery space for yourself, ideally near food, bathroom, water, and pain medications. Also any phone chargers (get looooong cables), books, movies, etc. can be set up around this area ahead of time.
Clean your home and do laundry before surgery so you don't have to worry about housework. Stock up on groceries and essentials as well.
Remove tripping hazards like rugs, cords, and clutter from your recovery area and path to the bathroom. Install night lights, grab bars, elevated toilet seats, shower chairs or other assistive devices if recommended. Some of these might be findable at your local buy nothing group (the circle of life for temporary medical assistive equipment is long).
Ask your doctor if you'll need special medical equipment like a walker, cane or raised toilet seat. Consider acquiring laxatives - especially useful if you're using opioids, but being immobile can make you constipated and you do not want to strain anything.
Pain Management
Buy over the counter pain medications ahead of time (confirm with your doctor or check online that these medications don't interact with anything you're already on- frankly you should check with your doctor what they are planning on prescribing you post-op for pain management and double check any drug interactions for that too online!). For chest/abdominal surgeries you may like having a body pillow you can tuck an ice pack or hot water bottle next to.
Staying Clean
Plan and set up a wash station ahead of time, since you won't be able to take showers for at least a few days (generally around 5 days). Ideally this station allows you to rest in a comfortable position with easy access to a basin of water, soap, and towels. Check your bandages for discharge, and have replacements and cleaning supplies nearby. Try to wear clothing that won't easily snag on any stitches you might have (this can be scary, but you're unlikely to damage anything by doing so - just be gentle).
Meal Prep
If possible prep and freeze meals ahead of time. Make sure you have lots of water near you - you're allowed to have multiple water bottles!
Mobility
You likely won't be immobile post surgery, but you should plan to expect extreme fatigue/pain for at least a few days just in case your body has a bad reaction to anaesthesia/surgery. Discuss with a nurse what they think your needs will be and use that information to inform your preparation (but also look online because your medical providers don't have the same insights as fellow patients).
Finally, create a plan of how you will get to your post-op appointments if you end up not being able to get there on your own. Also create a plan for how to get to the hospital in case of any complications.
Support
If you have friends that you know will be able to come help out, create a list of your needs and get your friends to sign up for particular items. This could be bringing food, coming over to watch a movie with you, doing dishes.
If you live alone, consider asking a friend to check in on you or stay with you at least the first few days. Or look into a home health aide.
Contacts
Create a contact list of your doctor's phone line, a nurse hotline, and any other phone resources provided by your doctor in case you have questions once you get home. Place this list in an easily accessible/viewable place or have it on your phone.
Pets and Dependents
If you have pets, arrange for someone to take care of them or board them while you recover. Pets may accidentally hurt you or you may not be able to care for them properly after surgery.