@SP1988 wait till it says ready once it says ready in ceac case tracker you can create your account via portal ustraveldocs
amd there you can make the payment to your visa
you can also schedule your consular interview via that account
now for the medical I’m not sure how they operate in Colombia. I know in Dominican Republic you don’t need an appointment you can just show up to an embassy approved medical facility and they’ll help you that same day.
I added a picture of the account so you can see what the page looks like