The fact that your out there running no matter what the distance is great .
There are plenty of shedules to follow if you choose to use them on the net just google (other search engines are available) 5 k schedules or training programmes you'll get load s . Runners world do some as well .
There's a site called map my run..where you can plot your run lt'll give you an idea of how far you've run.
Any questions you have or advice just ask away we're a pretty helpful bunch on here.
Your speed is pretty good, but when you have literally just started running after 15 years, there's really not much point worrying about your times or anything, just go out there and have some fun You wil improve rapidly as your body gets used to running anyway