Re: Organising content for recurring events / activities
Don’t worry, your English is very good.
To answer your question, I think you need to think about what content there will be on your site.
Will the volunteer placements remain the same each half-year? i.e. a school and (for example) at a charity.
If this is the case, you probably want to keep the structure of the site very similar so people can read and learn from what previous volunteers have experienced. You could automatically ‘tag’ data in each half-year period; this would let you find and sort the data appropriately.
If volunteer placements can be anywhere and different in each half-year period, then you might want to use Groups as a form of category – i.e. rather than having groups for Example School 1 and Example School 2, use just one group – ‘School’. Again, you could let users tag data with their specific placements.
EDIT: I’ve also re-titled this thread to make it a bit clearer as to the type of questions you are asking