I'm so happy I found this question, as someone who's taken the LNAT Twice, firstly you want to get used to the jargon, so reading newspapers and articles, professional ones like the guardian, helps with the questions and the essay will most likely be on a topic which is very current in the world, also the last time I did the lnat, I got a math question, it wasn't hard but definitely surprised me. you need to do practice questions and papers to get used to the layout, the essay is very important, I saw people getting 39/42 and getting rejected because of their lnat, so there is weight on the essay as much as the questions, there are loads of books or websites which provide practice questions, I used this book on amazon called
"The Ultimate LNAT Guide: Over 400 practice questions with fully worked solutions, Time Saving Techniques, Score Boosting Strategies, Annotated Essays. ... the National Admissions Test for Law (LNAT). Paperback – 20 Sept. 2021"
also look up the average lnat score for that university and try to aim for that or slightly above. if you want any more advice let me know ^^