how do you use the font size and colour?

[sarahdee]

i want to make my font bigger and also use the colours, i understand the colour font red but how do i make it bigger?

 

[Baileysmummy]

next to where it states font colour.. theres a box to the right to make it bigger.. font size!!

and you can do bold to..

 

[sarahdee]

ok i can do the colour but how do i make what im writing big?in yellow