Yes you can start with other foods instead of cereals. In fact there are many recent studies out there that suggest starting babies on vege and fruit purees as first foods could be way more beneficial than rice cereals. Popular first food choices includes avocado, sweet potato, pumpkin, apple, pear, carrot etc.
For me, I started my boy on cereals but he absolutely hates it. In fact he wasn't even willing to eat much til he was 9 months+. I had to try so many other purees with him. Now he's ok to eat most foods EXCEPT cereals. Sigh. But every baby is different, some likes cereals and some doesnt. Some like sweet food and some doesn't etc.
You can refer to this website for more info on weaning babies
Introducing Solids to Your Baby, Solid Food Charts for Introducing Solids to Your Baby and Infant including Starting Fruits, Vegetables and Meat