I don't know is this answer too late or not.
Starting with software to modeling, I recommended to use
Blockbench a free software with user friendly interface
After that, you must know your platform, or what this model will be used for.
Java or Bedrock?
Mods, Resource pack, or Server?
Quickstart - Blockbench This's where I start making with my model :D, and if you have more question there
Official Blockbench Discord is very active
