Alright, I’ve also filled up the coolant and washer fluid, gotten the Maintenance light off, and have all the tools I think are necessary for my first oil change. I got a book specifically for my car, plus there’s a guy in my building who is apparently a master of all things mechanical and electrical who has offered to help teach me the ropes.
I change the oil in my own cars as well as many others a summer long ago spent working at a garage. It can be messy depending on where the oil filter is, as when you take the filter out often oil will spill out from that area. If you are lucky, it will spill right into the pan you are using to catch the oil. If you are not so lucky, it will hit various parts of the car -- the exhaust pipe, parts of the suspension, etc. Think about finding a reasonably stout sheet of plastic you can wedge in there for a make-shift funnel to divert a gush of oil away from your car and into the pan. Could be an old bleach bottle you cut into a sheet.
Generally best to change oil after the car has been driven a bit so the oil is warmed up so it will flow. Use a proper-fitting closed-end wrench to get the drain plug out--do not bugger it up with Vise-Grips or a Crescent wrench. When replacing the plug put on a new washer if the car uses one or at least use the old one if it looks to be in good shape. THREAD IT IN BY HAND, and use the wrench just to snug it. The plug just keeps the oil in--it is not some sort of structural bolt and it just needs to be tightened by the wrench by hand. Some shops torque it down a ridiculous amount, which risks damage to the pan while also making it harder to remove later.
When changing filters, if this is the more common metal twist on variety, when taking the old one off make sure the rubber gasket came off with it. Put a bit of oil (new or old) on the gasket on the new one. If it goes on vertically, I prefer to mostly fill it with new oil first. The idea is that that avoids a slight gap in lubrication when it is started the first time thereafter. Other people think it is silly, but why not? An oil filter wrench, or a really big pair of Channel Lock pliers may be needed to get the old one off if a gorilla put it on. When replacing it, screw it down until the gasket makes contact plus one more turn.
Unless your oil fill cap is real easy to get to, get a funnel ahead of time. A funnel used with oil in a garage is a dust magnet--I store mine rolled up in a plastic trash bag.
The amount of oil to add should be in your owner's manual. All my cars have the amount of oil to use written on the plastic covers over the engines so I do not have to look it up each time. Add about 1/2 a quart less, then check it several minutes later and see if it needs more. The volume between the low and high marks on an oil dipstick is 1 quart. Keep an eye under the car for drips for a few days and check the oil level again the next day or after the first drive.
Get in the habit of double checking everything you did. Make sure the drain plug is tight, the filter is tight, the fill cap is secure, and the dip stick in place. It is easy to put in something by hand, take a phone call, then forget the rest of the step. I had "Pros" (back when I lived in apartments and was not in a position to do my own work) not tighten the drain plug all the way one time and not replace the fill cap another time. One reason to work on your own car: it is difficult to find anyone who can even do a good oil change.
Start saving old empty milk jugs or something similar that will hold a gallon or more to store used fuilds. Any auto parts store will normally take them and dispose of them properly for free. Also, oily rags wadded up have spontaneously combusted. Something about heat generated as the oil evaporates-a relative of mine melted a plastic tool box in the back of his truck that way. Do not wad up a bunch of oily towels and toss into a trashcan inside. Shops have metal cans with self-closing lids. I would put them in an outside trash can, and not wadded up.