I don't think it matters how good you are. Yes if you are no good it will be obvious but once you get over it and look at each drawing as a chance to try something new it's really helpful. The biggest mistake I think people make at life drawing is to worry about the current drawing instead of trying to learn as much as…
i think its good to be able to use a pencil quite well before attending to this, these classes are very expensive, and if you dont have a proper base of pencil skill, it will probably hit you hard. pick up as much as you can, every art form is usefull for your overall skills. and i always say they overlap, if you are good…