Hello Jimlad, welcome to Stamp Community.

Most of the stamps look to be a basic collection with a few nice looking ones in there.
I like cancels or postmarks and socked on the nose circular type ones make the stamp worth more. The Sudan camel stamp with The CDS (circular Date Stam) on it will be worth more than a regularily canceled one.
Topical or thematic stamps (airmarl, airplanes, birds, animals, knigs, queens, etc) can be worth more to those collectoras concentrating on that aspect or area of the hobby.
The Australia big side-faced King George V (5th) stamps (1 green and three red) may be scanned or photoed (best to scan) at a closer range to zoom in on details as some of thsoe (and many other engraved (carved) stamps have flaws and faults that make them worth more than regular stamps.
It all takes a learning of certain stamps which takes time but is rewarding in knokledge sorting and classifying and knowing you know how to see or sense a really good stamp that others may miss.
Or you can just collect or accumulate stamps by country or world or topic or a certain era or time period.
The Italian set of statues ( I think) are nice to have.
The Belgium railway parcel stamp with the circle cancel instead of the rectangular baggage-looking cancel is worth more.
Full sets are worth more than single stamps, except when the singles are the valuable ones.
Confusing, it can be, but fun learning and looking and searching and hunting.