The first thing you're gonna want to do is go into your options and controls. Change the settings so whatever is most comfortable for you - Personally i use the arrow keys for relax and normal and WASD+Arrow keys for higher difficulties. Or another set of keys that is fairly descent to use is ZXCV if you can get used to that.

In other words - Set the buttons to what you feel comfortable with and here are the suggestions.
-WASD
-Arrow Keys
-ZXCV
-1234
And when you go higher than normal difficulty you will have to start using combinations of the 4-key sets. an example would be WASD+Arrow keys. So just try a bunch of different combinations and find which one you like the best.

Alright well this section is pretty short and simple, Finger and hand placement.

In games like this you only want to use your Index, Middle, And ring finger because those 3 have the best reflex and can be positioned easily (If you have a more intriquite key binding layout its possible to use your thumb as well)

Anyway most gamers already know the usual
A=Ring Finger
W/S=Middle Finger
D=Index Finger

Also if your using arrow keys the same rules would apply but mirrored.
Left=Index Finger
Up/Down=Middle Finger
Right=Ring Finger

Also one last thing is make sure your elbow and wrist aren't awkwardly positioned or those joints will start to hurt later on.

Ok. so next is the color and athletic signals.
Here is the color and movement signals to the beats of the song.
----------------------
On the Ground-Normal
----------------------
Kick=Right-Pink
Hop=Right-Pink
Short Jump=Left-Blue
Short and Long slides are either Left or Right-Blue/Pink
Jump Dive=Up-yellow
Slide Rail=Down or Up-Green or Yellow
Slide Under=Down-Green
In relaxing difficulty the only color is Blue and Pink depending on how fast your running.
----------------------
In the Sky-Normal
----------------------
Up=Yellow
Down=Green
Left=Blue
Right=Pink
When a color has a line, hold that button until the line stops
In relaxing difficulty the only color is Green.
----------------------
Slow Walk-Normal
----------------------
Same conditions as the sky.
Up=Yellow
Down=Green
Left=Blue
Right=Pink
In the slow walk you want to have really good timing which is what we are learning next.
In relaxing difficulty the only color is Yellow.

The last thing we are going to learn now is Timing,
This isn't much of a long subject but it's very useful.

Before every Note or Beat your want to hit the button when either
A-Right before your character walks past the middle
B-If you wanna get Technical, about 0.33 seconds before you hit 1/4 into the Note/Beat.
That is the timing for getting the *Perfect* note combo.

Start out slow and work your way faster and you will be able to do harder and harder songs with higher scores each time if you practice enough.

I hope you enjoyed the guide and i hope it helped.