I too was a baptized Lutheran before converting. As everyone else said, get into an RCIA program starting in the fall. You’ll get all the basics there. Bear in mind, there’s no obligation by signing up for the class. Some will leave after the first week, some will leave near the end, and some will complete it and become Catholic. The whole point is for people to go there and learn all about the Church and decide if it’s right for them.
Personally, I was hooked after the third week or so and knew I’d be completing it (not that there weren’t bumps along the way after that).
Becoming Catholic was the best decision I’ve made in my life.
And to second what someone else said, if you have been going to traditional Lutheran services as I did, you’ll be amazed at how similar it is to the Catholic Mass. As I’ve gone deeper into the Catholic faith, I continue to be amazed at the theological similarities between Catholic and Lutherans (as opposed to other Protestants).