Hi Gary -
Personally, I haven't gotten into trading my own money. Quantopian offers the potential to trade someone else's money, without any risk (other than the "opportunity cost" of developing an algo that may get rejected...but I learn Python and "data science" in the process, so all is not a loss). So, the first cut probably is, do you want to trade your own money? If so, Quantopian no longer supports that option (although you can do research for free on their site).
If you are interested in writing algos for Quantopian, it is a whole different ball game. A top-level view is:
https://blog.quantopian.com/a-professional-quant-equity-workflow/
If your questions are framed in the context of this workflow, you'll be right in step with the Quantopian team (and the new contest rules).