the shoe question pops up here now and then so here's what i'd look at for parkrun specifically. its a 5k, not a marathon, and that changes the answer quite a bit
the course matters more than the shoe
- a lot of parkruns are grass, trail, gravel or mud, not tarmac. the course page on the parkrun site usually says what the surface is, worth a look before you go somewhere new
- road shoes on wet grass in january is like ice skating. if your local one is a muddy lapped course, a cheap trail shoe with proper lugs will do more for your time than any fancy road shoe
- tourists: check the course page before you pack, two pairs if you're not sure
what you can relax about over 5k
- comfort problems that show up at 25 km mostly dont exist over 20 to 40 min. so you can wear whatever feels light and quick, you dont need max cushion for this
- you dont need race shoes. plated shoes are lighter, in the specs i went through the carbon ones are around 60 g lighter per shoe than regular daily trainers (median men's us 9, from brand pages and review sites). nice to have, but nobody "needs" that for a parkrun
- the shoe you train in all week is a totally fine parkrun shoe
what parkrun is actually great for
- testing. if you've got race shoes for a 10k or a half, parkrun is the perfect low stakes place to try them at effort first. its not a race, its a run lol
- trying new shoes before a long run. 5k tells you pretty fast if something rubs
small stuff that bites people
- double knot. untied laces on the second lap is a classic
- cold mornings: shoes feel firmer and toes go numb, a slighly thicker sock helps
- dont wear brand new shoes on a pb attempt, do one or two runs in them first
and the shoe wont make you finish ahead of the guy with the dog anyway