It sounds to me like you're interested in "financial economics" or "money & banking."
Having an interest in these topics myself, I find that they are less about macroeconomics as a whole, which, in the mainstream formulation, is about national income accounting, aggregate demand, general equilibrium, production functions, the business cycle, etc., and are more about the microeconomics of particular markets e.g. the market for money, the market for bonds. I'd have a solid grasp of microeconomics, and then learn national income accounting (`C + I + G + X - M = Y` i.e. the sum of consumption, investment & government spending, less imports equals the national income (GDP/GNP), as well as the capital accounts identities), some ideas about the business cycle and maybe a bit about aggregate demand. Then I'd dive into something purely about money and banking. You'll have the tools you need to think about how markets work, and ideas like the efficient market hypothesis should make sense (within the frame of the model).
I learned this stuff in school, so it's hard for me to give great concrete advice beyond topics, but I've heard good things about Sowell's "Basic Economics," Malkiel's "A Random Walk down Wall Street," and then a personal favorite of mine Vernon Smith's "Rationality in Economics." The latter is truly insightful, but might be difficult if you don't have some of the ground matter (e.g. "what are supply and demand?" "What is a firm?") covered first.