Hi! I am sure you'll do fine with feeding your lo. How old is he/she? I started my ds at 4 mos and found that his belly wasn't ready for them yet. When we tried again at about 5 1/2 mos, he was more than ready and we still have to be careful about getting constipated.
Anyway... enough of that. There are several different recommendations about the feeding schedule. Anywhere from 3-7 days before starting another new food. I have been doing about 4 days and it is working out fine for us. There are books on the market that you might be interested in for making food if you are thinking about trying. It is really easy and much, much cheaper than buying food. The book that I use is Super Baby Foods and people talk about it all the time on this site. All you really need is a hand blender and ice cube trays. Depending on the food, you cook it, peel it and puree it, although not necessarily in that order.
Remember that feeding your lo doesn't have to be done on a rigid schedule and that you can change it up as you feel necessary. They say to start with rice cereal (and all new foods) only in the morning until you get past the magic number of days that you are introducing that food. Then you can move that "old" food to the next feeding and start a new food in the morning, and so on. Now, that being said... we don't do very much cereal if at all because my ds gets very constipated with rice and oatmeal. I am going to try barley, but I fear we'll have the same result.
We offer water with a little bit of juice mixed in for flavor (ds hates straight water) in morning and afternoon. You can also introduce a sippy cup at 6 months and it can take about a month of everyday use before your lo gets the hang of it. I only give 2-2 1/2 oz per offering and never more than 6 oz of water/juice in the day. I think it can fill them up too much.
So far, we have done apples, pears, bananas, prunes, plums, peaches, mangos, avocados, sweet potatoes, carrots, green beans, acorn squash, as well as the aforementioned cereals. If you want to try avocados at home, let me know and I will tell you how. It is all really easy... I am not good in the kitchen either.
Anyway, I hope this was helpful. Let me know if I can help you with anything else. Don't be too hard on yourself. I am a first time mom too and it'll all work out for us.