Old leaves just dry out, shrivel and fall off. I don't see much wrong at this point. It would be good if you repoted them, probably best in individual pots and in very well draining potting mix. The soil is probably peat, and that is not suitable to grow healthy succulents. You'll see when you take them out. Gravel/rocks on top is ok, but not glued. Looks like there is 3 or 4 different plants in there, they may have different watering needs.
Rina

Thanks for the advice. So is it better to repot them into individual pots and move them to an arrangement next year or is better to repot them into a new planter now? I want them to be healthy as possible. The planter has two drainage holes so is this a good planter or should I find something else? This is very new to me but I like the plants and want them to be healthy. It didn't come with any markers that tell how to take care of it. Also should they be outside or should I leave them inside the house?

The planter is good if it has drainage; what is important is the soil it is in. I suggested individual pots, since they may need different amounts of water. It would be best to research each of them to find out about watering. All succulents will do very well draining potting mix, good sun and not too much water. Outside is always better (unless it's winter); better air circulation and light. Can you see what is the soil like? Try to gently pray off the glued rocks (they are usually glued together, not to the plants), and see the soil.

Is it wooden container? You could possibly keep them together if you know how to water.
In order to get better ID, try to take photo of each plant; looks like there is gollum, 2 different senecios (mandraliscae and kleiniiformis) and either echeveria or grapto-something (not sure).
Rina

The soil looks like potting soil to me with a little perlite mixed in. It is very compacted because of the stones and even when you remove the stones, the soil has a slick feeling from the glue residue. Yes the planter is wood but I don't know whats between the planter and the plants & soil. I took more photos so hope this helps to get an id on the plants and whether they should even be together. I think you can also see the discoloration of the leaves on the flower shaped plant, they are yellow and squishy and thinner than the other leaves. Do I need to do anything to help that plant?

Yellow & squishy sounds like over watered succulent. The soil is probably all peat. I would take them out of that soil, shake off and/or rinse off all of the soil. Inspect the roots - if there are any slimy-soft-dry or black roots, just cut them off. You can pick off the soft leaves, they will just die off anyway. Leave it out of soil for couple of days to dry out, then plant in better - more gritty soil. It would be good to mix some perlite and grit together with very little soil. Don't water for a while after potting it in new soil (if there is any damage to roots, water may cause more problems). Do that with all plants.
Right after repoting, keep it in little shaded area and slowly introduce to more and more sunlight.
(Existing soil is compacted because it is water retentive. If you have grittier soil, rocks won't cause any problems. Sometimes, I use quite large rocks to support newly planted plants without any problems.)

Ok I can manage that. Do I buy cactus soil or do I buy something to add to the soil to make it gritty. I found the recipe for the gritty mix but I don't need that much soil since this is my only plant. Thank you so much for the advice, I'm glad I found this forum.

If you have only few plants, you can still make good gritty mix (without buying 50lb bags of 'stuff'...). Look for small gravel - even aquarium gravel (preferably not the 'smooth' kind) would be good. Get bag of perlite from any store (walmart, home depot, any garden center). I hardly use any soil in my potting mix, but if I was buying I may consider orchid mix. Make sure the mix has no more than 1/3rd of soil (or less).
You can use clean stones/rocks from original planting as top dressing if you like.
Rina

Ok thank you so much rina! You have been so helpful! I'm letting the plants dry out now. After I cleaned it out I realized that the planter is lined in plastic and there was so much water I could wring it out of the soil. I'm gonna head out tomorrow and get my supplies to repot the plants! Thanks so much for your advice!

Never use plastic for similar purpose...They can't possibly survive in muck for too long. That's the problem with arrangements sold in many stores - they may look nice for a while, but are not suitable for growing healthy plants at all. Another of my 'beefs' - terrariums. Glass, mostly enclosed, no drainage. And sold even in reputable garden centers. Very misleading - because it looks nice. There should be a disclosure that it is for temporary/display only...
Are you planning on reusing same container? If yes, don't use plastic to line it. Wood will eventually rot, but should last for a year or two (or more-depends what kind of wood they used). Maybe just buy few terracotta pots; make sure they are not too large. Not glazed ones, unless they have really good drainage.
I use lots of plastic pots, and they are fine.
Will you keep plants indoors or outside?
Rina

Initially I had planned on keeping the plants indoors but after reading through the forums I realize I need to keep them outside so I am trying to figure out what I can use to keep them in so they will be safe in my yard with small children. I have a very small front porch so my back patio is the better choice but I'm worried that plastic or even small terracotta pots won't be sturdy enough to last through a storm. I don't know if I can get the plastic out of the container because it's been glued in like the rocks but it would be a waste if it's going to rot anyway. So much to learn in a short period of time.