Will the lectures teach me how to change pose?

[gIdr0]

i want to make this picture as a reference

But i worry if i will be able to change the pose to anyone similar to this (2nd picture)

Will it be simple, or i should to look for another reference

[NP5]

Yes you can change the pose of characters.
The arms out top image is in part specifically designed to help that process so the attaching of the armature can join well to the mesh without conflicts with other parts of the mesh.
Looks a great project character!

[FedPete]

As NP5 explains, use a A- or T-pose for your characters, it will help to model and later to rig the model, to put it in a pose.