Most likely based on you usage you have to get atleast 50 tokens.
Token is a token, and doesn't have any restrictions weather user can only view or Edit. You have to control this using Security rules (Who can edit and who can not)
When you buy tokens you can install Qlik Sense server, there is no additional cost associated to get the server like we have in Qlikview. When you buy 50 tokens you will receive License Number and Control number. Those you have enter when you install qlik sense server.
In sense server you will create streams where you can assign users to it. so any app that you publish to that stream can be accessibly by the people who has access to that stream.
incase you are not willing to allocate login access to user then only one option is there u have to give user acces token
One user Access Token can be shared to 5 user and they can see the same application at the same or they can see the different application and different stream. only one problem is there if all the 5 user is accessing the same application
then selection will be reflected if some one clicking it will affect all the 4 remaining user