Land of Doran

You will notice early on in the game, in the upper right side of the screen, a Download button. Tap on that and it's going to start downloading some game resources immediately. You can do this after you've started playing, or later - it doesn't matter. Just make sure that you do it, because once you've finished the download you will be able to claim the reward for free, which will give you the following items.

Big Grow Pack (contains various stones and other upgrade items)
100 Sapphires.
500k Gold.
2x 150% EXP Potions.

Make sure that you claim this because you will have plenty of Gold then and the extra 100 Sapphires will help you later on in the game, so it's definitely something worth getting for free!

A very fast way to upgrade your character's power is to check out on the screen if you spot the Enhance button. That will appear whenever there is an upgrade which you can do, which will give you more power. I suggest that you keep an eye out for this and whenever it appears on your screen you should tap on it and a new small menu will appear which will tell you which features you can improve (Equip, Buddy, etc). Tap on one of them and it will let you quickly upgrade one of the options. Do this whenever you can make upgrades!

When you are in the EXP Dungeon there is a button in the upper side of the screen, which says Encourage. Tap on that and it will give you the option to select Gold Inspire which will give you more EXP! I suggest that you do this every time you do the EXP dungeon, which you should do daily. It will help give you a huge boost of EXP, so it's definitely worth doing it ASAP because it will let you equip better gears and thus let you become stronger.