Advice for transition to architectural drafting

I am currently a conceptual project designer at a corporate signage company. I want to transition to architectural drafting without having to quit my job, so I was wondering if this is possible through an online program if I can just learn the required software and create a portfolio. My job now is to make detailed architecturally accurate/scaled drawings but just for signs and signage systems, but we use architectural site plans and drafts provided to us in our own drawings so I feel like I am adjacent to it. However I have a graphic design degree and have only used Corel draw at my current position. What’s the best way I can transition my career, are there any online courses that will actually help me get an entry level drafting role?