How to remove outdated certificates or restore to default certificates?

I have certificates that are no longer valid. I do not know much about certificate. I would like to restore to a default list to ensure I have secure, up to date certificates on my iPhone 6 running 11 and my iPad mini running 9.3.5 (13G36), trust store 2015111600.

Any advice would be greatly appreciate.

Anddroid gives you the ability to remove/delete certificate. I have not seem that option with Apple. Don’t get me wrong, I use Apple because I believe they have better security. The higher security the harder to resolve the issue.