I will let others help you with the ID, but here are a few general observations about indoor succulents and terraria.
Light is often limiting indoors, and I would expect a north-facing window does not get much sun for half the year. Generally that's not a great place for succulents. What's important for the best health and form of your plants (and will help with watering) is actual sunlight through the window hitting the plants, not reflected or diffused light. A south, west, or eastern exposure (assuming you're in the N hemisphere). Ideally S orientation for the most light in winter. When they can see the sun for a couple of hours a day, they should be okay.

Less than that and you start to experience problems depending on the plant. Hours of daily sun is what you should shoot for, to the extent your situation allows that.
When I water my succulents, I like to get the soil completely wet (to saturation) and then allow it to dry out most or all of the way before watering again. These plants tend to like it when wet and dry conditions alternate, and they can break down because of changes on either side of the spectrum. When things are too wet (that is, when they don't get a chance to properly dry out between waterings, so the soil is always soggy) there is a risk of rot. When things are too dry (too much time elapses after the soil has gone dry, or the soil does not get wet enough when you do water) then succulents will usually work through their water reserves (shriveling, wrinkling, and dying leaves) to deal with the situation. That is what your second plant seems to be doing.
The problem with terraria and succulents is twofold. First, it's hard to get the soil properly wet without a drain hole, that is without creating a small lake at the bottom. And second, it's hard to get a handle on when it dries out (relatively closed system, often very shallow and sandy) so it's really easy to starve plants of water. Over time there is a sort of gradual attrition until only survivors remain. Succulent terraria look cool when they are first set up, but are not that easy to keep going long term in practice. An overgrown succulent terrarium is evidence of dedicated care.
Here is a recent thread on a related situation.
The thread "Terrarium issues" in
Cactus and Succulents forum