To effectively utilize your ETCS script for the TGV project in Train Simulator Classic (TSC), first ensure you have a solid understanding of how TSC integrates LUA scripts. Your ETCS lines should be placed in the appropriate script files that define train behavior, typically found in the Scripts directory of your train model. Focus on the main train control script, where you can integrate your LUA code for ETCS functionality. Use the TSC documentation as a guide to understand the required functions and events that trigger your script. Additionally, consider reaching out to community forums for specific examples and troubleshooting advice, as experienced users can provide invaluable insights into common pitfalls and best practices for scripting in TSC.