If I wanted to upgrade my aging PC, which parts should get priority?

Current Events

The PC I built like seven years ago is really getting up there in age so I feel like its time to upgrade and I'm probably gonna do it incrementally since that's a bti more affordable

First off, I know that MOBOs last a long time and are generally interchangeable, so I have a B350 PC MATE (MS-7A34) - is that still generally usable these days or would I have to think about upgrading that too?

The other things: 8 gigs of RAM, a Ryzen 5 1500x, and a 1050 TI. Also I'm still using an HDD and not an SDD
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David Bowie