Easiest thing to do would likely be join a local running group that has various training distances/pace groups

The one I ran with had two annual sessions for half and full training (a long with 5k/10k ).

When I was training for my first ultra (Yamacraw 50k) I just did the full plan with the training group + 4 miles extra on the long Saturday run. Typically I could find a fool to run them with me :)

At least some of Garmin watches have workout suggestions for daily motivation as well as actual training plans you can do. (Found in the connect app) I don't think the suggestions are always great but what you can do is see your training loads in the different zones and decide if you want/should do some intervals or not. My experience with suggested workouts is I can get multiple days of high intensity in a row which I know makes no sense but the watch is trying to get time in that zone in the "range"

I like Hal Higdon's website

A lot of the big running blogs do reviews of the big popular training plans. Some of them are available for free, or are listed in their books. Personally I like he 80/20 plans. The focus is on doing a lot of easy slow building, but still keeps a wide variety of training runs. They have some good complementing strength plans too.

Unless you’re at a pretty high level, I’d start with the free plans Garmin offers with their watches. Someone else already mentioned it, but it’s the daily suggested workouts.

If you don’t have a Garmin watch, then you can buy some nice programs through training peaks that displays through their calendar and can sync with pretty much any fitness watch. I think runners world has a handful of their programs on there for like 20 or so dollars.

I’ve seen a lot of people talk about an app called Runna recent that’s suppose to do your programming for you. Haven’t used it, but if it does what it says on the box, that also may be a good option. Runna is an ongoing subscription though.

Welcome back to running!