How can I verify the security of my MacBook after an Apple tech remained remotely logged in?

Did you initiate the Support call from the number here:

Contact Apple Support - Apple Support

Clicking a link in a Google search for Apple support has been seen as problematic as scammers will pay Google to have their link appear closer to the top of the search.

At this moment, I would recommend to post the free EtreCheck report using the Additional Text option when posting to see if there has been any software installed on your computer that may have been used for this Remote Connection or other purpose.No personal information is included in this report. Do you know what app was used to share your screen?

How to use the Add Text Feature When Post… - Apple Community

You would want to make sure the changes to your Login and Apple Account password occurred AFTER the connection was closed and if not, change them again. There is not a specific log that will track what changes that occurred in those 2 hours.

Tamlouie wrote:

If he was a true Apple tech (which I did hear other agents in the background, but I suppose that could be recorded chatter?) why wouldn't he disconnect remote access when he ended the call or at the very least be disconnected when starting another support call?

People who talk to scammers often hear other scammers in the background. Hearing other people talking in the background just suggests that you were talking to someone working in a call center, whether that call center was one belonging to Apple Support, or one belonging to a scam "business".

The whole point for the call was with security issues and now I am unsettled and not sure if I compromised my security further. Is there any way to know for sure? Where could I look to see if his specific access during those two hours did or changed anything? Are there any specific ways or guidance suggestions for this?

At a minimum, you would want to take Mac Jim ID's advice:

"You would want to make sure the changes to your Login and Apple Account password occurred AFTER the connection was closed and if not, change them again. There is not a specific log that will track what changes that occurred in those 2 hours."

The question would be whether the session left unwanted stuff behind, like a key logger or other spyware to steal sensitive information and relay it back to a scammer.

You may also want to check Settings > General > Sharing and make sure that any sharing options that you aren't using and don't want to use are turned OFF. But without knowing whether you called a legitimate Support person, or a scammer, it is impossible to give any absolute assurances as to what might have happened.

Did the "tech" ask for payment in cryptocurrency or gift cards? If so, you were chatting with a criminal,

Tamlouie wrote:

Are there any specific ways or guidance suggestions for this?

Recognize and avoid social engineering schemes including phishing messages, phony support calls, and other scams - Apple Support