IN my opinion, there's really no hard and fast rule as to which you should offer him first.
may i know how old is he now?
lots of PDs recommended that we should start weaning process slowly only after 6months old. and with that in mind, it's also merely letting babies learn to understand and try the different types of texture/taste. and not so much on filling thier little stomach up with solid. as milk asn still be thier primary source of nutrients.
just my 2cents......