To what extend I have to improve my skills at solid works?

1- First, Design intent you must consider the design intent before modeling.
Design intent is your plan as to how the model should behave when it is changed.
The way in which the model is created governs how it will be changed.
2- Start with SolidWorks Tutorials
3- Start to study these section Modeling, Drawing, Assembly, Advanced Part, Mold Design, Sheet Metal, weldment.
you can do these by yourself (Youtube, online SolidWorks Help, www.solidprofessor.com) or take Courses in Certified training center
4- then you can start in Simulation division (Plastic, Simulation, Advanced Simulation, and Motion) this link for Solidworks Video Tutorials (almost courses) By torrent http://torrentcrazy.com/torrent/3510166/solidworks-video-tutorials Please don't hesitate to contact me for any further question or assistance

For general Applications;

 

Sketches: fully defined

Modelling: Advanced

Assembly: Based on requirement, you must be comfortable to make sub assembly and do it faster

Drawing: Most important. You must be capable to do professional drawings.

BOM: Auto generation.

Sheetmetal is recommended.

 

For Advanced applications:

 

Configurations

Design Table

Driveworks (Auto Generate drawings too)

Rendering

Auto Assembling, Configured BOM etc

 

I provide trainings for CAD tools. If required, feel free to contact.

and do exercice

Surfacing , assembly , part/assembly configurations, weldmet , sheet metal and drawings with GD&T call outs. Most important thing to become a designer is to know how the you design will get manufactured. DFM option in soludworks will help you to some extent but practical knowledge is essential. All the very best !!!