Park Runs are weekly (Saturday mornings at 09:30am) 5 kilometer runs around local parks. They are free to take part in. Local runs are at Springburn Park, Tolcross Park, and Strathclyde Park. There are plenty of other runs around and bagging part runs (like bagging muros) is a fun Saturday morning activity.
Saturday 9th June is being dedicated to the NHS for its 70th birthday. Details can be found at: http://blog.parkrun.com/uk/2018/05/12/dame-kelly-holmes-backs-parkrun-for-the-nhss-70-birthday-on-9-june-to-get-the-nation-active/
Local Parrun web pages are:
If you are looking to build up fitness to get to a 5K run, the the NHS podcast NHS Couch to 5K, available from Apple istore, Google Play, or wherever you get your podcasts, is an excellent resource.
And don't forget the Santa Dash at Christmas. Now is the time to start training.