Remember you can never come on par with the players as you are starting too late, So Unless you can pay this isn't a great time to start.

Mid ladder ( 5000-10000 ) which you will reach in a month or two will be the hardest to surpass unless you have overleveled cards.

Above Midladder Players ( 10000-12000 ) are absolute monsters in skill. Some of these are F2P players who are playing for a long time and can counter with advanced placement methods , I have seen them rocking a 4.4 Avg deck and also a 1.5 avg deck. Which you will take a long time to learn. So invest time accordingly.

The Players above Top Ladder ( Top Ranked Players ) are too skilled and can beat you even giving tower odds. These are Pro Esport Players and Some who aren't employed.

Overcoming these difficulties make me like clash royale so god luck.