There are some sources and starting tutorials you might start exercising even if you never hold a brush.

But anyway you should be skilled in sketching to paint loose and free style without pencil.

So start from sketching before and don’t stay here for long if your heart call for freedom. Don’t stay in a cages of lines if you want to paint with freedom, atmosphere and style.

Seems like you already SEE a DIFFERENCE! For sure paintings without sketch is more alive, fresh, atmospheric:

Original watercolor baby deer painting by Olga Peregood (2018) without sketching before

Original watercolor muscari painting by Olga Peregood (2018) without sketching before