I strongly recommend purchasing (or viewing online) the Compendium of the Catechism of the Catholic Church. My edition of the Catechism has over 900 pages and 2865 articles; my edition of the Compendium has 224 pages and 598 questions and answers; that's one-fourth the size with the content distilled into one-fifth the material. Each of the questions in the Compendium is cross-referenced with the Catechism. The Compendium has the same general arrangement as the Catechism.
The Compendium also has an Appendix with two dozen common prayers (most in vernacular and Latin side-by-side) and a dozen "formulas of Catholic doctrine" (e.g. the Beatitudes, the three theological virtues, the seven corporal works of mercy).
I'm considering making a searchable version of the Compendium just like I've done with the Catechism.