Controlled impedance PCB design requires experience on tolerances of effective relative dielectric constant and loss tangent for the choice of MANY different types of epoxy,fiberglass,polyamide, ceramic, teflon, etc materials. I suggest you start with Saturn PCB design tool if you dont have anything.
Then enter the frequency of interest, research suppliers with best material of choice ( low loss , high f , stable, reasonable cost) then consider tolerances are cheap for 0.1% R's but expensive for <10% on dielectric so Impedance testing costs money or find good supplier who can advise you on options.