****If you find the achievements for Advancing your settlments through the ages are nnot unlocking, try clearing the cache or alternatively uninstall the game then reinstall it, this should unlock any stuck achievements***
To upgrade to the Renaissance Age you need $1,150,000 or $1.15 million.
This can be achieved in two alternative methods (excluding simply purchasing the tokens)
First of all the most important feature of the entire game is the Battle enemies. If you want to play the game by not attacking and simply producing your own coins then get ready for an extremely long, frustrating journey. Use the battle system to search out enemies with large coin reserves and attack.
We live in a capitalist society it is easier, quicker and more fun to steal other peoples production. Every opportunity you get attack enemies and steal their coins, invest your wealth in upgrading the barrows. All three of your barrows need to be fully upgraded for you to store enough coins. If however you have say 700k you can use any tokens you may have earned to pay for the rest of coins you need.
Make sure you have good defences. But more importantly take time to ensure your base layout is effective Dont build a wall around your base and have all of your buildings inside. This is pointless, an enemy simply needs to break one section of wall and their army can rampage. Instead, construct walls in grids or sections so that the enemy has to smash down multiple walls, this slows their advance allowing your defences more time to resist. Click on Clans, then leaderboards and select any player in the clan and view their base. You will never see all the buildings within one large wall.
It takes three days to upgrade once initiated so bear in mind you will lose a builder until complete. and once your command centre changes the achievement will unlock.
Personal advice would be to upgrade your base sufficiently before simply rushing to get this achievement. Regardless of your trophies once you upgrade you will notice that you get tougher enemies to fight.