What system do you suggest for ordering tickets and make bookings?

I am starting a business where my studio will be open for people to come and participate on specific days. The studio will be open every Monday and Sunday during set time frames. These days are fixed.

I will be selling tickets, allowing people to choose when they would like to visit and how often. Each ticket will be valid for one year. Generally, these people prefer flexibility and often decide the day before when they want to attend. There is a limit of around 30 participants per session, and I already know that 30 people are interested in coming to the studio.

It would be helpful if the payment and invoicing system doesn't require much effort on my part. I would also like to create a system that allows me to track visitors in person. If people are required to show their ticket, how can I monitor how many times they have visited, especially if they have a ticket that allows 20 visits? I am open to both digital and analogue systems. One advantage of an analogue system is that I could provide a stamp card to track attendance (my business is not highly susceptible to fraud). I also have a WordPress website.

There will be three types of tickets available:

1. One-time only (priced higher; I expect people to pay in cash for this)
2. 5 visits (moderately priced)
3. 20 visits (lowest price per visit)

My requirements are:

• People must be able to pay digital
• I need to offer three ticket options which people can order and pay
• A booking system that allows people to reserve a spot

It would also be nice to have:
– A way to track which people visit. However, I think providing each person with a card which gyms have might be too complex (these people like simplicity).
– I need to send a reminder via mail