What martial art could I start to learn?

I’m a 24 year old lad with no martial arts experience. With a few bouts of ‘milling’ in the forces as my only experience.

I’m very keen in learning a martial art and am swaying more towards jui-jitsu. Anyone with any experience can give me a bit of insight to what each ‘style’ offers.

I’m a fairly robust when it comes to fitness, so that shouldn’t be an issue.

Cheers