If you've never been to a con at all def aim for comfort and safety your first time. Many people have over burdened themselves their first time and end up having to tap out and ruin their own fun time.
For spending, it really depends on your area and cons around. Cons where you don't need a badge to get in the building, just in main areas, you could try dipping your toes in the water by hall con-ing it. Put on your best merch and hang out, you'll see PLENTY of cool things, as well as getting a feel for the atmosphere and seeing if it's something you'd like. Or going on a Sunday where half day tickets are very cheap.
If you can get lucky you might have friends in the area you can stay with or be a short trip away to save on hotels, and you can of course bring your own foods.
Cons are worth it if you can handle a lot of noise, crowding, and stimulation. But, you might just find your people there!