Solid foods

You may refer to this website for introduction of solid food. https://www.healthhub.sg/live-healthy/1227/baby-getting-ready-for-solids Try on egg yolk first instead of egg whites, as egg whites contain more allergen than egg yolk. Give egg yolk bit by bit till your lo can finish the whole egg yolk and if no allergic reaction means you baby is okay with egg yolk. After 1 year old, start giving your baby egg white and observe for any allergy reaction.

Yes it's good to slowly introduce common allergens like egg, dairy, fish, nuts in very small amount to baby's diet, it's not only to find out if baby is allergic but also can help prevent allergies later on. Some vaccines do contain egg white so if you haven't introduced it the doctor may ask you to stay for an hour to make sure there's no reaction before going home.

I started with fruits before introducing vegetables follow by grains (cereal / oatmeal).

I intro as plain food as possible like plain congee or rice cereal.

just slowly introduce allergens