Hello, can someone please help me with these question?

Case:

A researcher designs a cohort study to estimate the risk of 30-day readmission after knee arthroplasty. She wants to find out if patients who received spinal anesthesia have lower risk of readmission compared to patients who received general/other anesthesia. Patients were followed 30 days after surgery to determine readmission. The researcher identified 78 patients who met the inclusion criteria for the study and followed them. She found a Relative Risk of 0.65 [0.51-0.81] comparing those with spinal anesthesia to those with general/other.

How can I approach to the following questions:

What could be another method to calculate the effect size in this study? How can you go from relative risk to effect size?

Based on the level of measurements identified for the independent and dependent variables, what would be the recommended statistical test?

Explain what represents the type I and type II error in this example. Apply the errors to the practical exercise using the variables identified.