Bonjour and welcome
the CZ is an excellent choice - CZ makes high quality firearms, from their pistols, 22 rifles, centerfire rifles and the 858. If I was looking for a firearm in that class, it would be my first choice.
I personally own 2 CZ's sporting rifles and no doubt to quality.
Ammo is plentiful for the 858 as well.
now if this was my very first firearm, I would have to ask "why the 858?" Personally not where I would start with my shooting.. if the answer is "cuz it's cool"