hii! i got 28 on the LNAT this year, and these are some things i learned from it.
Firstly, it's only half true that it's an aptitude test. Practice makes a LOT of difference, especially when it comes to getting familiar with the format of the exam. imo, start doing weekly practise at least 3 months before you take your test
You need to know what exactly the question is asking and without practicing, you might misunderstand.
For example, if they ask you to "infer" something from the text, you have to know that they're not asking you to pick an option that is a direct statement, rather something that you can deduce and conclude from the text. The LNAT is time bound, so thinking about this during the test can be really stressful. if you want to maximize your score, make sure to do lots of papers, and critically analyze where you went wrong.
I used Arbitio, and it helped me a lot. While I think the arbitio LNAT essay marking was not particularly helpful, their MCQ tests were challenging and the explanation really helped me understand how to tackle the LNAT. If this is too expensive for you, there are a lot of LNAT resources online that are a lot more affordable. (the oxford uni website has 2 free ones you can check out) Oh, and definitely go through the sample test on the official LNAT website.
If you're someone who learns better through video explanation, check out Jesus College Oxford's "How to smash the LNAT" on YouTube or Eve Cornell's LNAT video.
Secondly, for the essay, make sure to have a format. Ishaan Khosla on YouTube has a really good take on how to answer the essay portion, in my opinion. It'd be a good idea to check it out.