Career Selection

I have not worked on designing practically before.

currently working as QC Welding inspector

You have not worked as a QC person earlier either. So what is the big thing?. Go and ask your organisation/ any other one where there is an opening as design engineer. If your basics are strong, you will get the appointment and then you will learn the actual on the job fromyour seniors.

As we say we do not learn from our mothers womb _{though doctors contradict on this now} (and that is doubly true in our trade). Now after 25 years in trade i realise i got only the theories in class room. it did made the foundations strong but the superstructure was built by experience adn the seniors in the trade. After all your would be boss will be your mentor (and most likely your success will be his in some cases literally too) Be confident, brush and strengthen your basics.