If you genuinely need mobility, install AutoCAD LT on an external SSD (not a USB flash drive) using the official installer. The software will still require registration on each PC, but the files remain portable.
The search for leads to a product that is technically compromised. While it might offer a fleeting moment of convenience by avoiding an installation process, the trade-offs are too severe: you risk infecting your PC with malware, suffering data loss from crashes, and violating software licensing laws. download AutoCAD LT 2018 portable 64 bit
Requires internet; advanced features need a paid subscription. If you genuinely need mobility, install AutoCAD LT