Great that you give it a try! The script looks great, I think you are well prepared.
A) Notetaking: Here is my strategy, consisting of two steps:
1- Take notes in the interview. Don’t write carefully, grammatically correct. Only write verbatim if the words of the participant are super interesting to you. You do it right if it looks messy
2- Essential 2nd step is talking time directly after the interview to correct, clarify, rewrite your notes, basically clearing up the mess and filling in gaps etc.
If I invest the time for step 2 I usually get rich interesting data. Have a look at https://jdittrich.github.io/userNeedResearchBook/index.html#recording-data for a description of note taking and audio recording (If anything is unclear: Write me and I improve the book)
B) If your participant agrees, record nevertheless. Sometime uncertainties concern only some parts in which even a mediocre audio can help. Smartphone is fine, even better is a dedicated audio recorder (since they can have a directional microphone – less backbround noise)
C) The hardest part for beginners seems to be to ask open questions that encourage participants to tell stories and describing situations they have been in. Just in case you struggle: It happens and is part of the learning.