Hi Frank2 - excellent question - you've certainly come to the right place.
Here on COPD.net, we have a wealth of published material which focuses on the use of supplemental oxygen and COPD.
For your convenience, here are links to several articles for you to begin with. Should you want additional material, please let me or any other moderator / team member know!
We can start here, with the basics: https://copd.net/living/101-the-who-what-when-where-why-how-of-supplemental-oxygen-therapy/.
And next, this article, which focuses on safety 'do's and don't's: https://copd.net/living/dos-donts-supplemental-oxygen/.
And finally, this article, which explains oxygen levels and supplemental oxygen: https://copd.net/living/oxygen-levels-supplemental/.
I do hope you find them to be helpful in a practical way. As said, we have quite a bit more should you be interested.
Wishing you well,
Leon (site moderator COPD.net)