I’m not sure where you live, but in California the application workflow is not well designed and very opaque (ie, some questions are unclear and you don’t realize you made a mistake until you’ve already submitted it, so then you have to call them to get it fixed).
As far as picking a plan, just compare the costs and plan details like you would if you were picking from a selection of company sponsored plans. And be prepared for insanely high premiums for terrible coverage.