Doesn't look like a succulent, it's a Croton, Codiaeum variegatum. A bit hard to tell but it is buried too deep in the soil, and that could be part of the problem. Is it a cutting, or does it have roots?

It has roots

Seeing that the roots are coming out the bottom I'd be inclined to repot and keep the growing tip up out of the soil. Does that outer pot have drainage holes? Crotons need good drainage.

An early lesson I learned the hard way, perhaps applicable, perhaps not, is that when moving, in some vehicles, plants may 'cook' surprisingly fast.

ETA, I hadn't thought of it but someone elsewhere reported damage to some houseplants from just setting in the sun between locations during a move. 'I just moved and then something just happened' does seem to be a recurrent theme on forums.

It could also be the air is too dry. It had been in a greenhouse someplace..and homes dont compare. Crotons really are bad houseplants. If you want color and indoors..try the new Aglaonema varieties. EASY to grow and a riot of color.

and make sure that the pot on the outside is not holding water that will keep the roots too soggy

I've grown them fine indoors 'til they got too big for my space. Yours looks like it sunburned & yes, planted too deep.

They're not succulents at all, their thinnish leaves really do burn as you learned. These plants need abundant watering, since they're tropical.

I'd make sure the soil is fast draining, add a pebble tray & to keep such color, give it maximum light you can but w/ GRADUAL exposure so as not to burn it again.

Depending on where you live, it would probably benefit from a summer outdoors in mostly shade.