Can you connect with other local gardeners? Everyone I know has seeds left over from last year and are probably willing to share, along with lots of advice.
Your own compost takes a long time to develop, and it's never enough no matter when you start. I have finally given up and I just toss it all into the beds, ready or not. We have chicken straw mixed with kitchen scraps that are both old and new. It all gets buried anyway. I call it guerrilla composting.
Depending on what your neighbors will tolerate you can easily plant in such things as bathtubs from recycle yards, like ReStore. I plant tomatoes in stacks of tires I removed from the landfill before the powers that be put a stop to it. I painted them green, which turned out to be wasted effort because we then had to circle them with metal sheeting to keep the ground squirrels out. All of this saves my aging back as well as money.
You do have to find reasonably good dirt to fill your tubs but I am also doing a little heugaculture by piling wood scraps (untreated) and broken limbs in the bottoms along with not so good dirt and then straw, chicken straw if you can find someone cleaning out a coop. So, less added dirt in the long run.
Starting a few tomatoes, peppers, broccoli, etc. indoors saves having to buy sets. Our challenge here is protecting them from the cats. Some years are better than others. And my last piece of money saving advice is to stay out of commercial green houses for as long as you can stand it.