Think if u read from Internet there are different schools of saying cereal is good and while some say no good ...
For the first few weeks is more like trial and error, practice eating, chewing and note for any allergies, I believe any food in low risk category is fine. After that can mix with food eaten before while introducing new types of food to gradually cover a full meal with carbo+veg+protein+fruit.
Not every babies like eating cereal, so better look out of samples or buy in small pack only.