You can download these from established community sites. For instance:
Instant Construction and Instant Recruiting (Recruitment). Where to Find v1.08 Trainers Command and conquer generals 1.8 trainer
Add 1 General Point or enable Unlimited Points. XP: Instant 5-Star General rank. You can download these from established community sites
WeMod offers a modern application that automatically detects your game version and applies compatible cheats. Command and conquer generals 1.8 trainer
PlayGround.ru hosts several versions, including the popular uniQ +7 trainer for v1.08.
Cheat Happens provides trainers that support both the original retail and "First Decade" versions. Usage Tips & Alternatives Command & Conquer: Generals Cheats and Trainer