no you don't.
make a circle in photoshop, double click that layer to open style options and press things until you like the way it looks.
example of what fast editing 3 circles (ish) without anything extra could give you.
Rest resides with brushes patterns fonts and some form of an idea.
Find pictures you like, rip parts of them and twist them to do your will.
Just like being a warlock m8!
Also youtube is an endless ocean of knowledge.
Yea most of the times endup using it one way or another.
Gimp is cool but in the end you will endup with photoshop so why not start with it.
Do enjoy Analog Efex Pro 2, Color Efex Pro 4, HDR Efex Pro 1 & 2 but that is more in regards for editing photos and not this kinda of mishmash. all of them are not free but there are ways ofc.