Can I upgrade the RAM or CPU in a 2010 Mac?

Start by checking the exact model and screen size before buying RAM. A 2010 MacBook Pro has replaceable memory, but the maximum is disputed here: 8 GB and 16 GB have both been suggested. Verify the limit for your specific model before ordering.

Also check the required memory type and speed, not just the capacity. A cheap stick advertised at a different speed isn't automatically a safe match.

For the 17-inch 2010 MacBook Pro, the CPU is soldered to the board. Even if a newer i7 looks related on paper, that doesn't establish that the board will support it. I'd rule out a processor swap as a practical upgrade.

The 2017 machine is a different situation. Its RAM is soldered, so that's not a normal upgrade. Storage may be replaceable on some models, but check the exact model first because it can require a specially designed SSD.

Software is a separate decision from the hardware upgrades. You could leave the 2010 machine on Sierra rather than assuming the newest system is the best fit. Check the exact model and compatibility before considering a newer version.