I'd strongly recommend looking at volunteering opportunities in areas that interest you. Without any relevant experience, companies will be reluctant to take you on, especially if you're well clear of school leaver age. Volunteering gave me the chance to try a handful of things at the same time and once you've demonstrated a bit of willing and enthusiasm you'll often be trained and tasked with things that could take you a long time to get to in paid employment.
I decided I wanted to work in either food or conservation. Now, after volunteering and then working in both I've decided to focus on conservation for the time being. Food generally involves a type of pressure and more anti-social hours than I'm prepared to commit to so, barring a rare daytime small production opportunity, conservation is better suited to my lifestyle.
I'm now working seasonal work for the local authority's Parks and Outdoor Spaces Team (the same LA I rage-quit my office job from) while saving up to get tickets in woodchipping, pesticides and basic chainsaw felling.