Do not use search engines. Instead, use a bookmarked internal URL such as:
Many VPN providers (including self-hosted OpenVPN solutions) package the clientca.pem inside a .ovpn configuration profile. You can extract it: clientca.pem download
Let’s assume your system administrator has confirmed that the file is available on a corporate portal or an internal Git repository. Do not use search engines
Yes. For Windows systems that require .crt or .cer : Do not use search engines. Instead