as a CRE my qualifications for catechist are basically the same as for godparents and confirmation sponsors: you are a fully initiated adult CAtholic (includes teens who have been confirmed) living in harmony with CAtholic moral teaching, including church laws on marriage. You are someone who lives their Catholic faith and is eager to learn more. You may not be a theologian or have a certification but you love Jesus and love His Word. If you have a family you are doing your best to raise good Catholic children.
WE can teach you what you need to know, but I cannot put faith where it does not exist. As I told the parish my first year here when trying to recruit Catholics - give me 12 people with strong faith and we can transform this parish.
Catechist is a calling, and one who is called to this all-important vocation (not a career or job) is given the charism by the Holy Spirit. We are all given charismatic gifts by virtue of Confirmation. Some to be priests, some deacons, some to teach, preach, administer, serve, prophecy, speak in tongues, interpret tongues etc. All CAtholics are called by virtue of baptism to evangelize, to spread the good news of the gospel in whatever circumstances of your life. If you are called to serve as a catechist, but decline to serve that is a very serious disobedience. By the same token, not all are called to be catechists. If you feel a strong call to learn more and to teach it but not to work with children, consider working with adults especially in RCIA.
If you are already doing several other ministries in the parish, then do not become a catechist. Discern which ONE of these ministries is the one you are called for. If you are doing too much, you may be taking the place of the person whom the Holy Spirit has designated for that ministry. Think about it, pray about it. Don’t worry about what you know or don’t know, that can be remedied if you sincerely desire to learn.
If you are one who got shanghaied into teaching, and handed the manual and a roster, my advice is this: spend one hour in preparation for each hour in the classroom. Start by reading the scripture passage and the Catechism paragraphs given in your catechist manual for the lesson. Meditate on what you read, then make a lesson plan. The day before the class, gather the materials you will need, pray again on the scripture. Before class, pray again, and pray at the beginning of each and every class session that the Holy Spirit will be the teacher, and you will be His instrument.
Team teaching is preferred in every classroom, in fact, there really should not be a classroom without two adults present. If you don’t have a team member, recruit someone, your DRE will bless you unto the 3rd & 4th generations.