Hi! Could anyone help me out with my problem, I'd like to make a carbon bath, but the most nesessery thing about this project is good looks without anything accept carbon and good enough grip so that it won't end badly. If you have any suggestions leave them here please!

A lot of cases where "grip patches" are added can be done by adding very fine sand or grit to the mix to make a rougher surface in those areas.  However, on a clear resin such as this, it will compromise clarity heavily so may not be an ideal solution.
 
Alternatively, you can get stick on grip patches specifically for baths.  Some are black, some are clear "ish".  

Warren Penalver
Easy Composites / Carbon Mods - Technical Support Assistant