You're gonna have to be a bit more specific than just '3D modeling'. Are you looking to actually make figures for say Daz? For that, you'll want to either look into Blender or Poser. Or are you looking to assemble and make a character/scene with a posed figure (Daz, for example.)? Assuming you have the proper hardware (for Daz, you're going to want 16+GB of RAM and at least a 2060, though you could opt to go lower if you're willing to wait longer), the best place for anyone to start on anything is with tutorials.
Working under the assumption that you're looking for an introduction to Daz,
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,
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,
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were all super helpful picking up Daz for the first time. Specifically Parmy and his beginner videos.