My DS is 9 months and only has 2 teeth and we do BLW. I always give him a spoon to mess about with and he does really well with his food now. Last night he had mushy peas for the first time, as long as you can live with the mess it's really good fun
Ds wanted to be fed anything not obviously finger food as.quickly clocked it was quicker than doing it himself. Dd grabbed spoons and insisted on feeding herself even if it wasn't going to stay on easily, followed by tipping the bowl into her mouth.
Sticks of meat or fish worked really well, chip shaped potatoes, pasta shapes, any cooked veg, pieces of fruit... though I also gave meals with sauce but spoon-fed - the finger foods were great for keeping babies occupied while I sorted the rest of the meal out.
Mine started to crack loading her own fork and spoon from around 17 months. She would happily scoop up anything mushy with her hands before that, as long as it wasn't too hot. We would pre-load spoons but she liked getting stuck in with her hands. It was lots of fun to watch!
DD didn't get any teeth til she was 13 months old. I didn't do BLW back then as I'd never heard of it but she had finger food all the time, from being 4 months (as age recommended at time). Never had any issues at all - she used her gums. She could manage anything with no teeth - veg, fruit, fish, meat - even remember having a piece of steak at Christmas, all with no teeth.
Babies gums are quite hard and they can chew surprisingly effectively.
Don't give raw carrot or apple sticks as small bits can break off and be a choking hazard. You can, however, give a whole apple (with a bit of skin removed) and they can scrape little bits off. Most other foods are fine.
To start with, it helps to cut foods into stick or wedge shapes so that younger babies can pick them up easily. Sticks of steak or chicken go down well, and obviously bits of soft fruit and cooked veg. My DD's favourites were celery, falafel and homemade pancakes.
To start with, most BLW babies don't digest very much, but by about 8-9 months they are usually quite good at eating. In any case, milk is supposed to be the main source of nutrition for the first year, so to start with it doesn't really matter how much actually goes down.
If you feel their gums they are rock hard, and they are quite capable of dealing with virtually anything. You only really need teeth for meat lumps, and if you cut that into strips they will just gum it until all that remains is sad grey connective tissue