That's what I think too. The brown leaf can't turn green again, plant would look better if you take that off, but glad you left it on for the pic to show what's going on. Looks like it has a toxic buildup of something in the soil, likely fluoride, to which this plant is very sensitive. Over time, some tap water can alter the PH of the soil also. Has it ever been repotted? The next time it's dry, I would flush the soil with a gallon of distilled (not bottled drinking water) or rain water if possible. Pour about 1/4 of the gallon on it, wait 15 minutes, pour another quart. Wait 15 minutes, then very slowly pour the last half gallon, all over the surface of the soil, not just in one spot. Then let it dry well before watering again. It likes very bright shade, but not much if any direct sun outside. In the house, some direct sun that's not during the middle of the day should be fine. Come on by the house plant forum if you have further questions or need instructions on repotting, best done during summer.

Strelitzia nicolai Here is a link that might be useful: White Bird of Paradise

Likely echeveria, or maybe a pachyphytum, or pachyveria. Maybe pachyveria clavifolium? maybe someone else will be more confident, or post photos once it blooms, it will be easier to say then.

By now you may have gotten an answer to your query, but if not the Fl Dept of Agriculture, County Extension Service may be most helpful. I have contacted them in the past with good results. Every county has an office, so just look up the dept of agriculture and find your county. The contact information will pop up. You can then submit your photo and contact info. I'm sure they will be able to identify your mystery plant.