2 months assuming you mean an autoflower? nutrient dose depends on a few different factors for a beginner, first and foremost your medium and knowing what you have already; some soils come with nutrients already in them, aside from seedlings usually having enough stored energy to survive without nutes for a short period of time. For photos and my type of medium, other growers wait to feed after 2-3 weeks have past, or when the plant shows signs, cotyledons dieing off ect. For auto it may be a little more scaled ahead as they enter flowering faster, and generally finish faster considering photos can be kept in veg n trained ect.
I have not grown an auto myself as of yet, but they might be a little different when it comes to feeding schedule compared to photo. You will def want to keep things light, to be on safe side as recommended above, less is more. I will let someone help you on the nutes and what/how much to use specifically, not grown autos and only grown 3 plants so far in veg state so clueless as you are as to those brands ect. Good luck.