Vicky, welcome to the skiing community! I'm really happy that you had a good first outing. Keep us posted on your experiences when you get out on the hill.
As for painful feet, here as some thoughts.
As it's been said, there's nothing more important than your boots. I know people who ski in boots that are falling apart because they swear that they'll never find anything as comfortable again, who will never check their boots in when they fly in case they get lost, and many similar stories. The bottom line is that the difference between having boots that fit and boots that don't is the single biggest difference-maker to your skiing experience -- both how much fun you have and how effectively you do it.
So, if you're going to be a skier (and it sounds like you've been bitten, doesn't it?) then does it make sense to buy boots right away? You'll save money in the long run, of course, so it's tempting, but my advice, on balance, is to hold off for the first holiday. A little bit of experience will make you a more savvy customer next time round. The thing is, getting to that perfect boot fit is elusive (and can be very expensive). Boot guys will sell you all kinds of custom adjustments (footbeds, alignments, etc., etc.) and that can be necessary. But it can also be very pricey.
I'll tell you my own experience to illustrate.
I own two pairs of boots at present. The first one I got about five years ago. I went to the ski shop in the resort with the best bootfitting reputation on the evening of my first day's skiing. I spent a long time being measured, balanced, having custom footbeds made and so on. Then I skied the boots for the rest of the holiday, going back most evenings for some kind of adjustment. By the end of the week, the bootfitter and I knew each other pretty well (in fact, she's still a good friend) and I had a pair of boots that fitted. It wasn't cheap, but it was worth it.
A couple of years ago, I was in the resort at the end of the season and I realized that it made sense to have a pair of boots to leave in Europe and a pair to have in the U.S. In the last week or so, the resort tends to be empty and there isn't much business in the ski shops. Also, they are having end-of-season sales (the shops close in the summer). So I walked into a shop -- in fact, the same company that I bought my other boots from -- and took about twenty minutes of the bootfitter's time since there weren't any other customers about. He had all kinds of bins of odds and ends and he went through them giving me things to try on. Finally, he gave me a pair that weren't end of the range (but there was an overall 40% discount) and they fitted right off. I bought them, skied them the next day and didn't need a single adjustment. In fact, I didn't even bother to put my custom footbeds in them. As it turned out, they were made by the same company as made my other pair but cost me less than half as much. When I went skiing the other day here in the U.S. I really couldn't remember which of the boots I had on until I looked down and checked.
All of which is a long way of saying that boot buying is a black art.
But here's the take-away message. If your boots hurt you, go back to the shop and tell them. Yes, boots are supposed to be tight so that you can transmit messages from your legs to your skis effectively, and some people are simply not used to wearing tight footwear. But there's tight and hurting. In particular, if your feet have red marks (pressure points) you need to do something about it. I used to think that that was simply part of the deal -- what you had to put up with when you went skiing. Learn from my mistake -- it's not and you don't!