OP - A good start would be to register your copy of Trainz as without a legitimate serial number you're not going to get anything from the DLS where 95% of Trainz content is hosted. It will also show you own the program and therefore likely to elicit more help.
Assuming we are talking about TANE on the PC here, the best procedural standard gauge track currently is probably that prefixed LRW. Not specifically Japanese but if you want proper looking points and switches to form when laying your route is the way to go. ISTR most Japanese railways are laid to 1067mm/3' 6" gauge for which there is some 42in procedural track but this has a more rural, worn look than a main line effect.