As software engineer with two architecture degrees, oddly enough, I can't really give a basic path for fundamentals. The reasons why boil down to architecture being something that is both functional and aesthetic, purposeful and monumental, with a wide range of directions, trends, movements, and motivations. Then there's the act of actual building which is an endeavor in and of itself.
My advice would be to start with a piece or several pieces of architecture and research the architect behind them. Explore more of their work along with other architects of a similar style or within the same movement (i.e. Le Corbosier and Mies Van der Rohe). Look at earlier buildings in their careers and compare them to later work and try to see what changed and why. Architecture doesn't happen in a vacuum and typically has rather reactionary elements to it, so what are those. Repeat this process with different architects or movements, and invariably you'll find a lot to explore.
Lastly, Architecture is experiential, and it's tough to simply look at drawings and understand space. Two of my favorite buildings are thousands of miles and thousands of years apart; the Pantheon in Rome, and the Seattle Public Library by Rem Koolhaas. The reason why I love both buildings is that there is nothing that comes close to being in those spaces. Regardless of the the design, methodology, aesthetic, or history of either building, the space evokes something.
That's a meandering non-answer, but that's my take on it.