For myself, it's not about avoiding ANYTHING that comes in a package...I eat Kashi cereal, buy Bob's Red Mill steel cut oats, use a lot of cannellini and black beans - all these things come in some sort of bag, box or can!
When I use the words "prepackaged", I typically mean it in terms of snack foods, processed foods - foods that either are usually full of empty calories, or where the food no longer bears much resemblance to the real thing. Foods that have long ingredient lists, that contain chemicals, artificial colors, HFCS, trans fats, etc. I try to eat as many whole foods as possible - foods that are as close to they way they occur in nature. An example would be an apple instead of commercial apple sauce or juice. Steel cut oats instead of Quaker instant. Brown rice instead of instant or even white.
I do typically eat whole wheat pasta, whole grain bread. I do most of my cooking from scratch, so yes - things like pasta sauce, I make my own. Keep in mind, though, that I love to cook so this isn't a chore in my eyes! You can certainly find good quality commercial products - it isn't so much about never eating anything pre-prepared, but rather making good healthy choices and putting quality first.
(and also - I control what I can control. I'm by no means militant - I do go out for dinner to restaurants, friends' houses, etc. and don't freak out about having white pasta or whatever on occasion.....life is life!)
I do eat plain yogurt, but I like it - I wouldn't make myself choke down anything I couldn't stand the taste of. I think the key is you have to enjoy eating this way - it definitely isn't for everyone, no matter how many people like the idea of it. I think a lot of people that don't eat this way would be pleasantly surprised if they did it for a while - but everyone has to choose what works for them.
I think that the changes you're making sound good - you shouldn't feel like you have to jump head first into the deep end!
You may find that, as you make these beginning changes, that you want to go farther. Then again, you may decide it just doesn't work for you. The bottom line is that if you don't like how you eat, it isn't something you'll stick to.
It's definitely more than fruit and chicken breasts, though!
I eat oats with fruit and yogurt, whole grain toast and natural peanut butter, omelettes loaded with veggies. Roast salmon, fresh turkey breast, sweet potatoes, sauteed spinach, fruit salad, greek couscous, brown rice pilaf, big asian stir-frys. I drink chai tea, and enjoy dark chocolate now and again. There really is a tremendous variety of really whole, healthy foods out there - and limitless ways to prepare them. I'm definitely never bored!