I would advise to buy a premade soil optimized for Cannabis rather than trying to make your own. Inevitably you will just end up with crappy soil. Promix HP (white bag) has perlite and mykos added to straight peat. This is a ‘soilless’ medium and ought to be used as intended IMO.
Sand will add to the density of your medium and do the opposite of what you want. Perlite and Vermiculite are good and if you want increased drainage raise the ratio of your medium to everything else: it’s designed for drainage.
Now if you want to make your own soil there are recipes here floating around but are pretty complex and expensive.
Here’s the link to his recipe: