General concern, particular issues or errors shown, are you a criminal or investigative journalist or political dissident or are you with direct or indirect access to sensitive or classified or financial data, or do you have any particularly rich entities unusually interested in you?
It’s unlikely for most of us, unless it’s been downloaded onto the iPhone by someone with access, or unless you’re a target of a very wealthy adversary.
Most “spyware” around works by accessing iCloud or local backups, which means securing your Apple ID and encrypting local backups. The expensive tools are targeted at very specific individuals, based on all available evidence.
No app store apps can scan your iPhone, for instance. Not absent an exploit, or more commonly series of exploits.
If you’re concerned about your security and privacy, update your passwords and passcode and password-reset paths, enable two-factor authentication, set up a trusted recovery contact, set your trusted telephone number, keep updated to current, and related steps. Maybe reset and reload your iPhone, and install only the apps you know and want and need, as malware persisting across a reset is Really Rare.
Some reading: https://help.apple.com/pdf/personal-safety/en_US/personal-safety-user-guide.pdf