Modelling:
you need to model a base shape , then sculpt it to add all the details( using a tablet, its abit like working with clay but all virtually ofc).
each model is made out of small triangles , when you add details you add more triangles, each triangles needs to be computed.
This means more details = slower renders , computer lagg = bad ( you can run out of ram and then you cant render out your image)
retopologizing
Once you have your sculpted model you need to do another model with alot less triangles and then you use something called baking to save all the details to an image.
Then you apply this image to your model with less triangle , and now you have model that looks like the model with alot of detail but has less triangles.
Texturing:
Well now you have the model but it looks grey, so you need to create the colors or "materials" for your models , you dont only chose the colour you chose if it shines , is transprent , glows and such.( it can become quite complicated)
For simple materials like the headband of my jelly bean its simple because you have the same colour everywhere , but for the green skin material of the jelly bean it gets more complicated and you need to paint the colours on the model on your own.
the material can get really complicated in the end:
UV-mapping:
But ( yes there is allways a but), you cant paint the colours directly on your model, because your computer doesnt know how to link the colours that you paint to your model, the only way is to paint and link a 2d image with your 3d model, but you need to tell the software where he has to cut your model to unfold it, else you get distorsion in your colours.this is called UV mapping.
mapping an image to a cube:
It is easier to model character when they are in a T pose, but in your final scene you want your character to have a nice pose that tells a story, or defines your character:
so you need to put virtual bones into your model, and link them to the parts of your model.
after that you can make him pose in anyway that you want.
Now you need to do the scene and the lighting, you might need to retouch your material because you now have a different lighting or viewing angle.