Just some thoughts;
Ditch the knobby tires if you have them. Just the noise will drive you nuts.
For urban riding I rode for years with a cheap "be seen" lights. Street lights were enough to see. I finally splurged on a Magicshine and it's nice for the trail portion of my ride.
I wear a regular construction safety vest - ALWAYS when I commute.
I also didn't get bike specific rain gear for a few years. Being a camper/hunter/fisher I had a couple different sets that worked fine. 80 & rain is way different then 40 & rain, Rarely wear my rain gear in summer unless it's a downpour. I bought a nice pair of cannondale rain pants at the thrift store for $2
I ride 26m/day on road bike and wouldn't do it without bike shorts. I had a pair and have added more as deals come along.
I wear a stiffish soled pair of athletic shoes. When I replace them I look for flat stiff soles. I use cheap plastic $5 strapless Mt bike toe clips from REI. Quick in & out and still some attachment and foot placement control. Some day I may go clipless. Below about 20 - 25 I wear a pair of hiking boots. I love smartwool bike socks and other merino long socks for cold weather.
In cold weather I bought some Craft XC ski pants I love. Thin fleece lined, full length leg zippers for venting. Bought another pair recently on sale. Tops I had some duofold and other long sleeve henlys in wool blends and hi tech fabrics from hunting/skiing etc. I've purchased some smartwool stuff on clearance and my daughter bought me some really, really nice Icebreaker merino tops for Xmas. I have various gloves to fit the weather, but when it gets real cold I use a $4 pair of ski gloves from Menards. I have to turn them inside out during the day to dry as I will often sweat in them.
Summer tops were whatever. I've since purchased wicking tops from thrift stores, sales, swaps etc.
My 22 YO Trek road bike daily rider won't fit fenders. My hybrid rain bike has fenders for known rain days. You don't need two bikes but I subscribe to N+1
I don't own a bike without a rack. Most bought on sale or Ebay as well as pumps. I bought a used pair of panniers form a guy at work for $20. Used them a number of years and purchased a new pair at REI scratch & dent sale for $35, sold the old ones for $20. I also got an old pair of Kelty tourpacks in a $5 box O'stuff at a gear swap. These fit my kids bike for rides such as the fireworks when we need to bring more "stuff"
Oufitting yourself can be done over time on a budget, keep your eyes open in thrift stores, especially near high end neighborhoods where people buy the good stuff and wear it once. Most gear can be had on sale both on line and locally, gear swaps are another good place to look.
Another option is to find a good place to park part way to work and multi mode commute until you build up the strength, resolve, whatever to do it full distance, full time. I started out parking at one of our other locations and riding 4 miles and doing extra riding after work until I was ready to go the distance.