Can you copy? Do you mean to boot from SSD and just swap to SSD for booting? If so, read up on SSD cloning software particular to that make of drive. Experiences vary. 😉
250GB SSDs tend to be slower than larger drive in sustained writes. It's not something I would worry too much about, short of writing a lot of data regularly. Generally speaking, the 500GB drives are the sweet spot of capacity to performance to price per GB.
Having said that, it might suit you to get a 1TB SSD so the cloning process is 1TB to 1TB. The Crucial MX500s are very affordable for the GBs you get if looking at 2.5" SATA SSDs. If considering NVME, I recommend the Adata SX8200 range.
Moving to SSD will give a better performance improvement than the RAM, but...