Probably poor soil, too much water held in the soil, pot possibly too big, plant too low in the pot. Is it always outside? I think it could use more light. Get an appropriately sized pot with a drainage hole and fast draining soil. If you read other posts on this forum, you will learn a lot. Succulents store water in their leaves and so do not need a lot of water.

The pot seems to be too big. Try getting a smaller pot and set it's roots down where the soil is evenly flush rather than having the soil mounding. What kind of soil is it in? I would definitely start with the basics.

Leaves that start yellowing and are soft are most often water logged.

The most important would be to give it good drainage - pot with drainage holes and very well draining mix. Mounding up the soil is not problem - it actually helps to direct excess water away, but in water retaining mix it helps just a little.

Big pot + water-retaining mix = very big chance of rotting.

After these are corrected, the plant will need lots of light.

Yes the plant is always outside @socks thank you guys for all the help. I will try my best to follow your advices. One more question though, aren't losing leaves at only the bottom part of the plant normal? Thanks again!

Sometimes yes!