They don't need teeth to start fully weaning lovely 🥰 But as above as long as food is cut and cooked correctly they can try absolutely anything and everything bar I think honey, whole nuts and things like popcorn and hard sweets!
Not sure if I understand your post, teeth aren't essential for eating solids. Have you tried anything besides apples? You will need to introduce common allergens one at a time with a few days in between and just go slowly with increasing quantities and varieties. Bear in mind little tummies can react to lots of things so keep an eye for signs of constipation, rashes, things like that. Consistency wise my lo preferred mashed up or pureed food at first but you can do some research on the baby lead weaning too. Or do combination of the two. Some things are not safe like honey and stuff that can be choking hazzard, google search can give you all the info on that. Most kids are curious at this age and would be happy to try some of the Thanksgiving dinner, just make sure it is safe for him to eat and you can offer small bits.
Solid starts is a great resource for all things solids. They have a fantastic app. You can search a food and it will tell you how to safely prepare and serve it. Usually they are ready to start when they can sit independently around 6 months. Starting allergens as soon as possible and continued exposure is good to reduce the risk of allergens
Don't start with fruits they should be introduced last. veggies raw or steamed 😊
Go to solid starts but they can have food at 6 months and honey after 1. They don’t need teeth to eat my kids didn’t get teeth till closer to 1 and have been eating since 6 months. Don’t do anything hard. Make sure things are mushy or easily able to be chewed.
Just started doing Quaker oatcakes with peanut butter spread on top! It's cheaper than getting teething crackers 😆
Everything!