There are many threads on here for USNA event discussions, including if you had to choose whether to attend I Day or Plebe Parents Weekend (PPW). I Day you arrive day or so before with your appointee, spend some anxious last hours together, deliver him/her up to USNA in the AM, wander around until the late afternoon induction oath (tear-bringer) and precious 15 minutes' bye-bye time. PPW, near the end of Plebe Summer, you get much more time and get to take them off-Yard for hours at a time, but usually not overnight.
Fall of 2/c (junior) year, there is 2/c Parents Weekend, usually coincident with a home football weekend. 1/c year, Commissioning Week!
Depending on how close you are, Army-Navy Game, Bowl games, sports events on the Yard or road, concerts, etc., might be things your mid tells you about.
Above all, the minute you identify an event, book the hotel (threads abound). You and thousands of others descend on Naptown with regularity.