I agree on a used enlarger--as long as you can locate one that has all the parts with it. Getting a discontinued enlarger without all the condensers, negative carriers, anti-Newton ring glass plates or a lens board can lead to a lot of frustration. Luckily, there are lots of good quality enlargers out there at bargain prices these days. A 4x5 enlarger is a good choice only if you intend to go to 4x5 film later on or if you can get one cheap. There are a number of enlargers that will print up to 6x7 or 6x9 that are well-made and, usually, less expensive.

A good easel is important. A 4-blade easel can make impressive photos but a 2-blade is a lot less expensive and will work.

Get a set of trays that are a little larger than the prints you are making. Believe me, if you don't you will quickly understand why you should have.

Start simple. Use easily obtained, standard chemicals. Don't experiment with a lot of different photo papers until you figure out how one paper responds to your negatives. Variable contrast papers can save you money and offer an advantage with split filtering techniques. It may be best to start with RC papers to save time in processing. You can always try fiber based paper later.

You can wash your prints in just about anything as long as there's water available. A Kodak tray siphon is pretty cheap and it's efficient to use with an oversized processing tray. A dedicated archival print washer is even better but not necessary in the beginning.

For processing film, you can choose plastic or steel. Plastic reels are easier to load than steel. If you step on one, it will break. Steel won't break but it will bend. A broken plastic reel and a bent steel reel are the Steiglitz "equivalents" to useless. I'd say start with plastic and switch to steel if you decide to. Both work.

Get a good thermometer and check it against one you know is correct. I've been using the same thermometer for 30+ years and adjusting other thermometers to match its readings.

You don't need a film washer. You can buy one of those cheap shower sprayers with a hose like those at Home Depot. Take the shower head off and throw it away. Keep the hose and the rubber slip-on connector. It makes a good film washer when used with your processing tank. I dump the water occasionally just to be sure.

You're gonna get a lot of advice. Good luck.