I would like to know how to download cubase to my computer, and what folder should I download it ot
Welcome to Yamaha Synth, Sidney.
Your question is very vague and you give us no details about your situation (computer, Operating System, purchase, etc.) We'll make some assumptions... we'll assume you purchased a Yamaha MOXF (given the forum heading), we'll assume you are the original purchaser of the instrument and have received all the in the box documentation... and while things can vary in different parts of the world, we can give you a general idea of the procedure (base on what happens here in the USA).
In the box with your brand new MOXF is a "STOP Don't Throw Away" card with your Cubase AI DOWNLOAD INFORMATION... which thanks you for purchasing the Yamaha hardware product and entitles you to a free download... Cubase AI is a specially prepared entry level version of the Cubase DAW software with special Advanced Integration (AI) features for Yamaha hardware. The card directs you to a website where you'll find the Cubase AI download - it also provides you with the 25-character DOWNLOAD ACCESS CODE, that you will need during the process.
You will need a computer (Windows or Mac) with Internet access.
The following video shows in detail the process of downloading and installing Cubase - it will be the same for your MOXF...