I usually recommend for ppl to start with 2 grams. and once they get familular with the feeling, and experience, to try 3.5 to 4g for something more intense.
its kinda like this. imagine you have never felt or been in water ever in your life. 2 grams is like jumping in the shallow end of the pool, you get water up to your waist, and you get to feel what water feels like, and play with it. hey this is cool! and ur very much still in control of the situation, and very unlikely that your going to be able to do anything stupid in the shallow end. and u get to become familular.
Now imagine taking 3.5 grams is like jumping somewhere in the middle, u get water up to your nipples, and if uve felt water and are familular with it, it dosnt have to be that scary. but if its your first time, and everything is alien to you, it could potentialy be overwhelming, if u panic. but still very much safe.
Now taking 4grams and beyond is like jumping in the deep end. you might be safe, but u better learn to swim first. learn to be calm, and go with the flow. never fight it, and always remember, everything is very temporary, and everything will go back to normal, its just a matter of time.
Have fun!