Usually, especially when you are drinking Ayahuasca for the first time, during the first round, not much will happen.
It is new and often there is some resistance where the mind wants to keep control it. This blocks the Ayahuasca.

A second round of drinking is for most of the participants a breakthrough. The mind gives up eventually. Ayahuasca is doing her work and you’re making a connection with body, feelings and soul again.

Please note; it is a normal occurrence that resistance comes up before drinking the second drink. Know that this is the mind wanting to stay in control. Resistance is not wanting to accept it.
Stay curious, follow your breath and relax.

However; realize that it can be the case that the Ayahuasca brew is strong and that you are a very sensitive person. Then there is no need for a second cup and the process facilitator should respect this.

Note; in the South America tribes it’s very common that you have to drink 4 cups or more. This depends on different standards and the use of different plants as well.