Before buying any internal hardware for your mac make sure that is absolutely and definitely compatible with your particular mac. I would go direct to a known reputable reseller of mac compatible SSDs and RAM. As your mac only has 2GBs RAM then that is the bare minimum needed just to run the OS let alone any apps so yes upgrading your RAM will help. Installing an SSD will make a big difference as the internal drive that comes preinstalled in the mac is very slow, make sure that you have articles at hand on how to install these two items in your mac safely and correctly. How much you want to spend on your mac is up to you after all it is an old old machine and can only upgrade as far as High Sierra.
Before installing any of the items in your mac you will need to make a full back up of it to an external drive. You will also need to download a copy of El Capitan you can get it here, How to upgrade to OS X El Capitan – Apple Support
At Section 4 download InstallMacOSX.dmg. When that has downloaded open it and you will get InstallMacOSX.pkg.
Double-click on that and an installation window will open, this will convert InstallMacOSX.pkg to the
Install OS X El Capitan.app which will be in your Application folder.
Use the Install OS X El Capitan.app to create a new bootable USB installer, How to create a bootable installer for macOS – Apple Support
After that you should now be able to boot to the USB by Restarting your mac while pressing and holding down the option/ alt key till the Startup Manager screen opens there you select the USB and press Return. If working correctly you will boot to a Utilities screen with various options. You need to be sure that you can boot to your USB before installing the SSD otherwise you can become stuck. Oh and do not wipe the original hard drive you may need this in case it all goes pear shaped.
If you're happy you can boot to the USB then you can shutdown the mac and follow the procedure for installing the SSD,
https://manuals.info.apple.com/MANUALS/1000/MA1534/en_US/MacBook_13inch_Hard_Drive_DIY.pdf
https://manuals.info.apple.com/MANUALS/1000/MA1533/en_US/macbook_13inch_mid2010_ug.pdf page 46.
Once you have installed the SSD and the RAM then you will need to boot to the USB you made, and click on Disk Utility.
You now need to format the Disk, highlight the Disk in the left hand panel, click Erase, give the Disk a name.
Format: Mac OS X Extended (Journaled)
Scheme: GUID Partition Map
Click Erase.
After that has completed you are now ready to install El Capitan on your Mac. Follow the on screen instructions.
After that you can import back any important data you have on the back up you made prior to the installations. Do not import back any System settings just bring back data that was in your Users folder, movies images music personal info etc. If you import back system data etc you may be importing bugs and glitches in the old system that were causing your mac to slow down and you do not want that.
Hope this all works out for you.
