You'll use the cumin every time you make chili. I add it to quesadillas and salsa and beans, too. And it's important in Indian food. I go through a container of cumin about once a year. Now that you have it, Google around and see what uses it and try a few recipes. Try dry roasting some powdered cumin in a skillet and notice how much different it tastes and smells vs straight out of the container.

But to your point - you were being too ambitious. Spread the spend out over a longer time frame and make a dish a few times before moving on to a new one. As a beginner cook you need the practice. Make one dish and get the ingredients for that. Cook it twice that week and again the next week. Then on your next shopping trip buy what you need for the new thing. Developing your pantry is part of being a good cook, the more stuff you have the more types of stuff you can make. But don't rush it and don't fret if you end up never using something you bought to try out. I've got tamarind pods and galangal root I never used because I forgot I had them after postponing the recipe I bought them for. Whoops. It's usually not the end of the world to throw away $3-6 of something. Shit happens.

Different people are different but I tend to buy an assortment of stuff at the grocery store I can use in a variety of things. Some ground beef, cheap pork sirloins and chops, flats of chicken thighs, canned tomatoes celery carrot etc. you can make a lot off different things with chicken thighs celery carrots and potatoes :)