Yes, you should introduce yourself in a cover letter. In fact, introducing yourself to the hiring manager is the entire point of writing a cover letter!
In the same way you would introduce yourself to someone at the networking event, you will address them using their name, then tell them why you are asking for a moment of their time.
You don’t need to start with your name as that will be included in the header of your cover letter along with your contact details, LinkedIn profile and location.
Here is an example of how you can start your cover letter with an appropriate and professional introduction:
Dear Ms Wright,
I am writing to apply for the Account Manager position that I saw advertised on Seek on the 23rd March 2021. The role looks like exactly what I am looking for in my career progression and I am excited to outline some of the reasons I believe I would be an excellent candidate.
While there are some other cover letter opening strategies, introducing yourself to the person who are making the acquaintance of is the most professional way to begin a traditional cover letter.