Upgrade order? Given your current hardware?
Your CPU, mother board, and memory are all obsolete regarding compatibility with any currently available new hardware. Meaning none of it will work with any new AMD mother boards.
If your HDDs are SATA drives, they could still be used. If any are PATA, a few new boards still have PATA connectors.
Video cards will be Ok. Sound card will need new drivers.
You really need to start from scratch.