As others have said, every child is different. And 3 months is way to early to be starting solids - even though some doctors are still advocating it.
Dean is now at an age that is pretty "normal" - at least according to the AAP to be starting solids. Right now, with all his food reactions, I wouldn't go beyond stage one until you have made sure he is OK with a certain food. You could make your own baby food if you want. LLL advocates mashing bananas, cooked sweet potatoes, and ripe avocados for first foods. Most babies tolerate those foods and they are easy to prepare yourself.
Stage 2 foods start mixing ingredients, so I would be careful about those right now. Stage 3 they start getting chunky bits in them.
I didn't give Liriel much for solids until she was 8-9 months old. In part because she just wasn't that interested. Though she did get some at daycare.
If you don't already have one, you could pick up a hand food grinder sold in baby departments. They will let you grind up your own meats and veggies to an appropriate consistency - tough you may need to add a little water or EBM to it.