Hi! This succulent has been with me for about a week and I haven't watered it yet. The leaves are still firm. I'm not sure if it's stressed because I bought it in the mountains and here in the city it's hot. I just noticed this black spot yesterday, the other day it wasn't there. The lower leaves seem to be wilting too. Could it be rot or something else?

Should I take the leaves off?

The stem looks fine and the soil has been dry for almost a week already. I'm going to transfer it to a gritty mix next week. I hope it survives till then. :(

These happened to the lower leaves, I took them off because I have ocd. Should I do that to the other leaves too? :/

Hope someone replies. I've seen black spots like this on my other succulent and I just took the leaf of and it's still fine now. I'd like to know the cause or what it's called.
Thank you!