B.S.
Oatmeal will work from a bottle just fine. Just be certain you are getting plain oatmeal not one with fruit in it. You can open the nipple larger by clipping the opening in the nipple with the tip of a pair of scissors. It's simple enough to do. Or the suggestion of the Avent bottles and nipples is good to know, too.
Yes, the first foods are perfect for your baby (even second foods)...just enough for starting out. You can use them anyway you like. Ordinarily, you'll want to feed three meals a day and a snack between lunch and supper. But that's not set in stone, LOL. So experiment, use each new food three or four days before trying another new one...to watch for allergic reactions. Meats are usually added around 8/9 months and by then you can begin offering some finger foods....graham crackers, cheerios, Gerber snack items.
Just make it an enjoyable time for both of you.