WRT Herndon, you won't see your plebe until you see him/her in the boiling mass around the monument. They should have town liberty that afternoon/night, and you can take them off-Yard after they get de-greased and showered up. In general, that's the pattern. Others may have more specific insight.
Summers are a mix of leave block(s) and training blocks. Training can be completely away from the Yard, ashore or at sea, or out of the country. It can start and end in the Yard, with some away time. It can be summer school, voluntary (double majors, getting ahead in matrix, trying for VGEP [another thread], easing load on traveling athletes) or involuntary (academic OOPS). Blocks can be mandatory or elective in nature. Town liberty varies with each option. Your plebe will get plenty of briefs and will be signing up for his/her summer sked - I think after holidays. There is ALWAYS the chance for change and block swaps from original schedule. Just like the real world military.
All kinds of stuff happens after classes and exams end. Turning in uniforms for storage, briefings for various summer events, academic boards for the oopsters, honor/conduct/performance hearings, late-season sports, cleaning rooms, some days of what is called "inter-sessional" leave. Current and recent mids can pile on here. Your plebe will figure it out.
We counsel our sponsor mids, especially plebes, to not delay telling mom or dad if they plan to go somewhere else with a friend for any leave breaks. Stand by for those empty nest indicators to happen when least planned.