First time creating CC, problem with importing

Hey guys! 

I just started creating CC content, and this is my first object. I've made many stuff in Blender before, but don't have any experience with Sims Studio 4. 

I wanted to create a simple table, and tried to follow a tutorial on Youtube about UV mapping and nodes and stuff like that. But when I import my object into Studio Sims 4, it looks flat and very long!

The tutorial said to choose a similar object to what I wanted to create, and import into Blender. Then they said to delete all the lights, camera and rig. There were also a big plane underneath the table which they said to scale very small and just hide it into the table, and the four smaller square planes under the legs of the original table, they said to just delete. 

The tutorial just went straight into Studio Sims 4 right after baking the diffuse material, so I have no idea what I'm doing. 

Does anyone know what I have done wrong? 

For reference, I use an old Macbook air from 2017 with macOS Monterey, so I only have Blender 2.79. downloaded. 

Also, I have dyslexia and am not english, so sorry about the spelling and bad language!

TIA!