How often should SEO be updated? And is there a simplified "template" that can be used to save time?

How can small (1-person) businesses just starting out a) understand exactly what is needed to achieve a good SE rank, and is there a simple way to quickly yet effectively update listings/pages to meet the best practise SEO needs?
Also, how often should it be reviewed, and if so, what is the best method to do this without it taking a really long time if there are numerous products /collections?
Thank you :slightly_smiling_face: