I think you are right, and that milk is the main source of food until 1 year.
The advice I have seen (and tried to follow) is to try to breastfeed about an hour before you offer food, so that hunger is satisfied by the milk (and baby continues to take plenty of milk) but that there has been time to build up enough of an appetite to try solids when they're offered. It is actually quite difficult to do this, as your days get taken over by feeding again (especially with twins!), but it sort if gets you into a meals & snacks routine too.
A typical day for my breastfed babies at 7 or 8 months would be something like:
7am ish breastfeed
8.30am breakfast with me
11am breastfeed
12.30pm lunch with me
2pm breastfeed
3.30pm snack (mini yogurt/rice cake)
4pm breastfeed
5pm dinner
6.30pm breastfeed
Breastfeed through the night as needed!
It's a busy timetable! It didn't always work, sleep gets in the way, and I definately noticed a drop in Breastfeeding time and frequency at around 7/8 months. But with that plan in my head, I knew that whatever we managed would be a balance if Breastfeeding and solids, and we found a way through it :)
I found weaning difficult, because in order to fit in mealtimes I suddenly had to have a structure/plan for the day! That was a first for me, as I'd always fed on demand and let them nap when they wanted. I found going out for the day more difficult because I had to take the right amount of meals with me, so had to know where I was going/when I was coming back! I didn't BLW though because I eat too much rubbish so perhaps it will be easier that way.
Good luck! And just keep offering the boob whenever. Your baby will decide the right balance between food and milk :)