The essential role of the sponsor is to accompany someone on their journey of faith, provide individual instruction or advice in living a Catholic life, and witness that they are prepared for the sacraments.
How to Develop Parish Sponsors
Practical Suggestions for Godparents and Sponsors
In canon law a sponsor must (Paragraphs 872-874 in the RCIA book):
be 16 years of age,
be baptized and have received Eucharist and Confirmation,
be a practicing Catholic
be married in the Church (if applicable).
Characteristics to look for in a sponsor:
good interpersonal skills
flexibility and availability
an active Catholic
The ability to develop a personal relationship with the individual they are sponsoring.
Some potential questions to ask in interviewing a sponsor:
Why do you want to be a sponsor?
What aspects of your faith are you most excited to share?
Does your schedule allow for 1on1 time with the individual you are sponsoring?
Would you be comfortable with that? What other parish activities are you involved in?
Can you commit to praying for the individual you are sponsoring?