Every Catholic church is different. Many require membership. "Membership" generally stems from the envelope system. IE, you register as a member and then send in or place an envelope weekly with collection funds so they can verify your attendance and community contribution. I am guessing that contributions of time would also count. Unfortunately, many churches require you to be a member for a set amount of time before they will let you book the church. Thus, if you fall in love with a particular church you may need to be a member for 6/12 months before you can choose a date.
You will need to take pre cana and my church also had a pre marriage test that FI and I took separately and then went over the results with our priest. Pre cana is typically either an intensive weekend (you can''t share a room, BTW) or a class weekly for 6-8 weeks. There are a variety of pre cana organizations and it doesn''t necessarily have to be through your diocese or even your state. We went to another state because it was the only weekend that worked. It was kind of weird rooming with a perfect stranger!
We had a smidge more difficulty with arrangements because we were married in my family church but by our friend who is a priest from another state. If either you or FI are not catholic there is an additional portion to the test. If either of you have been married before you will need an annulment. If either of you have been married before or have children there is also a different pre cana offered to address specific concerns.
Most Catholic churches have limitations on what time of day you can marry. Typically churches have a vigil at 4/5pm on Saturday and weddings are not allowed to interfere with that mass. We could choose between 10am and 1pm. The rule was the parking lot had to be clear an hour before the vigil.
Each church can have additional stipulations. My church requires that you use their musicians. A cathedral nearby requires a bride''s shoulders be covered. Sleeveless and spaghetti strap dresses are prohibited without a jacket or wrap. Many prohibit flash photography or video/photographers too close to the altar. Make sure you ask very specific questions.
To be honest, you may run into trouble with some priests. Our friend, for example, often declines to officiate marriages if he feels a couple is using a catholic church as a "backdrop" for their ceremony. Despite being young, he is old school! Actually, he even told us he prefers not to officiate if the couple is cohabitating. (We moved in together after marriage.) You may have your best luck at a church where there is some kind of family tie.
Good luck!