How to find critical load in sap2000 solid model

Halo, I'm trying to define critical load in short column.
There are 3 types of short column that I'm trying to define, plain concrete column, steel-reinforced concrete column, and composite column with I-profile steel. Each type has two different height; 20cm and 60cm. So, there is 6 short columns in total.
How do I define these 6 columns using sap2000 to get the maximum load/critical load that the column can bear? Do I use 3D frame or solid model?
I'm hoping someone would help. Big thanks