I current;y have the option between upgrading two lower level structures (Barracks, Workshop, or Stables; any combination thereof) to lvl 3, or upgrading one structure (War Cathedral or Forge) to level 2. I'm curious which potential seasoned players would suggest; I'm still new to this, so I'm not really sure which would be better. Thanks in advance.
You should do T2's if they are available to you. Also, you should sell the T1's and replace them with T2's, but do them one at a time and straight to level 3 (this will cost just over 10m each). Once you have a couple of level 3 T2's, you need to start buying allies. Keep collecting allies or increasing the value of the allies you have until you see that your allies bonus (on the victory screen after a successful attack) has quit going up. Once you have max allies bonus, build another level 3 T2 and then check allies bonus again. Allies bonus, level 3 T2, repeat. Follow that formula and you will be land complete in no time.