Welcome to the Guild! In most applications you draw your curved line (sometimes I need to make the line invisible in my program), then type your text making sure that the line length isn't longer than your curved line (the line should be longer than your text for best results). Then you'd select both your text line and your curvy drawn line, then apply some function usually called "align text to path". Then the text attaches to your curvy line. You may alternatively add spaces before or after your text line to fit it better, but that's all it entails. (I don't know what software you are using, but "align text to path" is pretty common in both image editors and vector applications - I use vector (Xara Designer Pro 9).