The first time my baby snatched and tried to eat food, was a piece of cantaloupe from my plate, she was 10 weeks old! I did not, at that point, start to let her have solids, although I did start to watch her and notice an interest in food and utensils. I did let her play with spoons, tiny bowls, and cups, and a teether-feeder thing with a mesh bag (empty). I also got the idea to catch or save leaking breastmilk, and started letting her "play" with eating breastmilk from a spoon or cup. She would get so excited when she saw me with the tiny bowl of milk!
After talking with her doctor about it, I started letting her have tastes of things at about 3 and a half months. It never impacted our breastfeeding relationship negatively, it actually seemed to make her want to nurse more. And she never gagged, or pushed food out of her mouth, or had tummy aches, or anything but breastmilk-looking poop.
At 4 months I started letting her have very tiny amounts of real soft food mashed & mixed with breastmilk. I would give her like a single bite-size bit of avocado or yam, smooshed with a few drops of breastmilk. I never tried to make her take it. I tried to pay close attention and follow her cues and even feed herself at that tiny of an age.
I would never go around telling people to start their babies on solids as early as I did with my daughter. I don't think it's right for most babies. I think the 6-9 month range is more reasonable. But I also think it could be okay, depending on your baby.