We weaned early too. DD's paediatrician (we're not in the UK) had said she should be weaned at about 3/4 months as it would be good for her weight (she's stocky, let's put it that way). Definitely did the trick 😂. We've changed to another one who's less concerned with it.
By the time we weaned,DD had already been eyeing our food for ages, looking miserably at us from her highchair.
Anyway, we started with single mashed up fruit and then added veg later in the day. Sometimes we added a bit of spice (banana with cinnamon was a decided favourite, I know shoot me now). When a single banana wasn't enough anymore, we moved on to porridge with fruit for lunch and jars of veg in the evening with us. The jars came about because I was concerned that my husband, who does the cooking, was putting in too much fat and often he wouldn't get the consistency right.
Then at 7 months, she grabbed a huge piece of cake from a friend's plate, so I decided to give her bread for lunch. That obviously calmed her grabbing action at every meal.
Now at 1, she eats breakfast on her own, and lunch. And she's just started eating with us, including spicy curry. Though she still gets spoonfed in the evening, as that's the least messy.
Incidentally, had I wanted to wait to wean until she could sit unaided, she would have been 9 months when she tasted her first food...