You are an individual. There is no one else exactly like you. Only you have your experiences and memories.
Remember high school track or cross country? You had the summer off, and then 2 weeks after school starts you have your first cross country race. That is how the program ran, no time for light jogging. Few if any kids ran through summer. It wasnt good for you then and certainly isnt at 50 plus.
Not to put a damper on your ambitions you can decide to run a 5k when you are ready. But dont pick one just yet. You have a lot of body conditioning to do ahead of time. It may take you 2 to 4 months or longer before you could race. A 5k fun run is an exciting way to gauge your progress without pressure of performance.