Trying to understand basic fire safety upgrades

I’m trying to get my head around a few things and figured I’d ask here. My sister just bought a small workshop space for her craft business, and the landlord suggested that she should look into some basic fire safety improvements before moving all her equipment in. Neither of us really knows what’s essential and what’s just optional extras, and most of the info online feels a bit too technical. If anyone has dealt with a small workspace before, I’d really appreciate hearing what you found important or what you started with.