Terrariums are most of the time worse 'containers' for succulents. They usually look good at the beginning, plants may even grow well, but sooner or later suffer from poor drainage and lots of humidity. If my plants, I would remove them from terrarium and pot into suitable containers and suitable mix. It would help if you post a photo and also give more info regarding 'soil', watering and exposure.

Agree with rina - a terrarium or a container with no drainage like the glass container shown will be the kiss of death for any cacti or succulents. They absolutely need easy and fast drainage and a soil media that is nearly 100% mineral - very little peat or bark.

You need to repot into a container with adequate drain holes and with a fast draining soil mix. And as soon as possible!! If nothing better, a cacti and succulent soil mix amended well with perlite, pumice, grit or turface will work.

This is my first attempt. Im obviously not a pro. Does anybody know some musts when making a garden such as the one I posted.

Terrariums are best suited to high humidity, moisture loving plants - ferns, mosses, some smaller tropicals. And generally tolerate pretty low light levels. But not for any cacti or succulents. These need the "musts" outlined above :-) And lots of bright light or sunlight. You can do a combined planting or a dish garden if you like but different species often have different requirements and they really do much better if planted individually.

Any tips on transplanting my succulents.

I would not make garden as in the picture. Not with succulents, but if you like one, use moisture loving plants gardengal suggested...Can't tell what plants you have there - some are better if potted separately.

Take them out ASAP...get rid of all old soil. Dispose of it...

Check roots - if any are rotting (soft-slimy and dark color) or dry or broken, cut them off. Make a new mix - if you have only Cacti&Succulents soil, get a bag of perlite. Sift or rinse it. Mix well; min 50/50 or even more perlite (like 60/40). Pot your succulents in pots with drainage holes in new mix. Do not use 'drainage layer' - it is useless. If they lost all roots, do not water until there is new growth showing. If they have roots, start watering after day or two. Do not overwater - check with a bamboo skewer or chopstick inserted deep into pot (at least 3/4 deep) before watering...Slowly introduce to some sunlight...

You are a life saver thank you so much.

What should i do to save the rocks. Bleach them? Dish soap!

Try to wash them, if that doesn't work, bleach them. They could be used as a top-dressing, but may be too big for mix. What do you want to use them for?

Use some potting mix made for cacti and succulents.

Forget the terrarium for succulents. Find a different plant to use in that way.

Potting mix, sold in bags, made for cacti & succulents is mentioned here very often as not as well draining as advertised...that is why ppl using it add lots of coarse perlite to ir...there are many, many posts on this subject. Final mix should look like this (using photo supplied by Crenda):