What age/Era are you in?
What other GBs do you have?
Cattle Ranch is merely a supply building which you will tear down when you move up to your next age.
Suishun MIll is merely an event building. unless you get all the upgrades for it from the Event it is not worth building, so keep it in your inventory until the Event has finished and only build it if you do get all the upgrades. If not let it sit there in storage until the event comes round again and you can finish it off. One thing for certain. there will be another Event along after this one with yet another special building.
If you are just starting out it is more important to think of getting the basics built before you age up any further. So stay put in your present age. You should not rush to get up through the ages. you need to stay in each one until you are as strong as you can be, so you give yourself a good start in your next age.
CdM. Zeus, and Cathedral off Aachen are essential. As is Observatory as it will pay your guild dues if you want to get into a decent guild with experienced leaders. For supplies build Lighthouse of Alexandria. ToB will give you population so you will not have to build so many houses. NEVER build the Colosseum.
You say you are into GE Then ToR is and essential GB as it lets you get relics from which you can get special buildings you can build that will also give you supplies but they are smaller than the cattle ranch. You can also get troops, medals, FPs, supplies, dismonds and coin from GE relics.
