Hi
EdoardoMarzI would add my two cents. The GRE is a valid and strong test for your application. There are caveats to have in mind, though:
1) Not so many official mock tests are available on the market and the official practice questions, especially on the verbal side, are not as the GMAT has;
2) The greatest misconception around this test is that it is a vocabulary test. Totally false. In standard English, you have kinda 14k vocabulary words; therefore, it is impossible to learn such an amount of words in the students' limited time frame. The only way is to understand the sentence's meaning, which for a non-native speaker could be daunting. Even though vocabulary is a vital part of the preparation for the GRE
3) Particularly for verbal , only use official material in the crucial stage of your preparation. Even though the questions from Kaplan, MGRE , for example, are decent to practice
4) The quant side is pretty similar but easier on the GRE. However, geometry is still a huge chunk of the exam, and this could be a rock on the road
Here are the best free for the GRe we do have
Just at the two links above you can find hundreds of resources enlisted. Both quant and verbal.
Let me know if you need further assistance.