1st foods: given at 3months, more refined easier for baby digestion.
2nd food: given at 6months, a bit more texture.
3rd food: start at 9 months, more chucky,thick for the experienced eater that chews.
No worries, your son will be just fine. After 6 months if your child is still eating some 1st foods along with 2nd foods it's okay. Even if your child gets older but still has some baby food favorites there is no harm in allowing your child to eat it. My youngest will be 2yrs old in January and loves to eat a variety of things from baked Salmon to Gumbo, but she still enjoys Beech Nut Turkey 1st foods and Gerber's 2nd Food Harvest Vegetables with Mixed Grains, every now and then. So I keep a few on hand; makes for quick consumption. Plus, neither of my kids would eat baby food unless it was seasoned; guess they got use to spicyfood from the womb.
You are doing a wonderful job.