Tickera itself does not have functionality which would allow you to set limit on the number of tickets available on per event basis unless, of course, you are utilizing Seating Charts add-on in which case, the number of tickets is defined by the number of available seats.
However, by running Tickera alongside WooCommerce via our Bridge for WooCommerce add-on you can create and sell Tickera tickets like any other WooCommerce product. The main point of this is the ability to create tickets as variable WooCommerce products. In that case, you can have only one product declared as a ticket per event and use variations to represent different options. With this, you can maintain stock on the product level regardless of how many of each variations has been sold which directly allows you to set limit of the available tickets on per-event basis.
Also, when running Tickera alongside WooCommerce, you can use third party plugins for WooCommerce which then makes it possible to easily integrate waitlist functionality either by using their own official plugin for that (found here) or by using some free alternative such as this one.