Try to keep them somewhat clean along the way and not let dirt become too embedded.
Clean canvas or fabric shoes in a washing machine with a mild detergent.
Remove shoelaces and put them through the wash too. Replace them if they won't come clean, or if they become frayed or worn.
Clean leather shoes with a soft brush or cloth and then buff them with a leather conditioner to prevent cracking.
Air dry shoes; do not put them into the dryer; the heat can melt the glue.
When drying them outside, put them in the shade; excess sun can yellow some glues
Another place to dry shoes is on top of a dehumidifier
Touch up leather shoes and cover scuff marks with the appropriate color of shoe polish.
Links:
[1] https://www.momsteam.com/successful-parenting/guide-to-buying-athletic-shoes-for-children
[2] https://www.momsteam.com/sports/running-jogging/equipment/buying-running-shoes
[3] https://www.momsteam.com/successful-parenting/replacingon-athletic-shoes-even-if-no-signs-excessive-wear