First of all the summa theologicae by st Thomas aquinas but you need to read it with a manual i recommend "Aquinas, a begginers guide" by Edward fesser.
For abortion issues https://www.amazon.com/Roman-Catholic-Teaching-Abortion-Contraception/dp/0984613560
For morallity and evil
For lgbt questions https://ronconte.com/2011/06/27/summary-of-posts-on-homosexuality/