Hi Iris. I'm not Cathe, but maybe I can make a few suggestions.
I'm not sure what results you'd like to see, or if you want to increase your endurance, add more cardio, increase difficulty of choreography, add more muscle definition.... But whatever you're looking for, I'm sure you can find it with Cathe. She has an outstanding collection of videos.
A great place to start could be with Cathe's latest videos in the Intensity series, or with the CTX series. Not ready to commit to an entire series? Then try either Body Max or Circuit Max. Very complete, very thorough workouts. All of the videos I menioned above can be performed with the exercise equipment you already have. Sometimes Cathe uses heavier weights, but you can build up to that, or just stay with what feels comfortable.
Cathe's choreography is fun. It may take you a few tries to get all the moves down, but she cues great, and of course you have that marvelous rewind button on your VCR. If you really feel that you are choreography challenged, you can start with Step Max, the Wedding Video, or Step Heat. These are some of Cathe's earlier videos and may help you learn her choreography faster.
Also, take a look at the streaming videos. This may help in your selection too, but I do have one warning for you. After you try the first video, you may want to get more, and more, and more.... It's hard to stop with just one Cathe video.
Welcome to the forum!!!
Lisa