Congratulations! Very well done
The only tiny mistake I could find was a repetition of the link text outside the link:
<p>You can find more information about
<a href="http://example.com" title="List of important university date">
important university dates <!-- here ... -->
</a>
important university dates on our website. <!-- ... and here -->
</p>
Otherwise the task was perfectly fulfilled
Regarding your question:
I really don’t see a reason for using <p> inside <address> in this example. On the English site there is another example where it makes kind of sense:
<address>
<p>
Chris Mills<br>
Manchester<br>
The Grim North<br>
UK
</p>
<ul>
<li>Tel: 01234 567 890</li>
<li>Email: me@grim-north.co.uk</li>
</ul>
</address>
Here the lines of the address itself are grouped together with the <p> tag and phone/email are grouped with an <ul>. The solution code for the “Marking up a letter” task doesn’t have a <p> tag either.
Have a nice day and keep up the great work!
Michael