Even if you are not yourself a Teosto member you should nevertheless submit performance notifications on your performances. Whether the authors of the music you perform receive royalties for these performances is up to you. Ensure that the authors receive their royalties when you perform music created by other people.
Many composers and lyricists do not perform their works at all, meaning that their performing rights royalties are dependent on the performance information reported by other people. However, as a performer you do not have to pay Teosto anything; instead, the event organiser will be responsible for the performing rights royalties.
If you are an event organiser, familiarise yourself with Teosto event licences.