Sale of weekly seminars managed by my clients on Squarespace. What is the best strategy?

Hello.

I needed the opinion of someone who has been making websites for some time. My customers for the website: www.upoop.pt/bemvindo want to have an online store with a book and some merchandising. In addition to selling these products, they also want to make it possible to sell seminars only to members of the associates area. 

Do you think I should:

- Make an online store only in the reserved area (you don't have many options and as the seminars change weekly, I wanted the date to be clearly visible)?

- Use the event page with a separate payment link?

- Using Scheduling?

- Another idea?

Thanks in advance to anyone who can help me.