Improve performance of laptops

@dharmanireeksha not sure what you mean by "has 512 had" (I assume a 512GB SSD) and what performance you want to improve. Remember that performance is also dependent on your OS and you did not tell us what OS you are having.

I would suggest an upgrade to something like a 2TB PCIe M.2 2280 SSD. Prices are reasonable and I am partial to Crucial drive (personal preference only) or go all out and get a Crucial MX500 NAND SATA internal SSD which has the right form factor for your Lenovo. Buy one that you can afford :-) Prices are reasonable as well.

Going by the specs for your Lenovo, it accepts up to 64GB of DDR4-3200 NON-ECC SODIMM 260-pin 1.2V PC4-25600 RAM. you are a little lean with your 8GB. I'd bump it up to at least 32GB. Of course, this is where the OS comes in to determine the maximum addressable memory. For example Windows 10 Home 32-Bit has a 4GB maximum addressable memory but Windows 10 Home 64-Bit has a max of 128GB

You can download the manuals for your computer from here