Reviving white macbook (Early 2009)
If you really want to make your old mac happy I would say the best thing is the SSD. It will make it feel faster than it was out of the box and that is because it is. A RAM upgrade isn't really necessary and I would suggest investing that money over into a new battery. If the unit hasn't been used in a good long while chances are your battery will be dead or inches away from death.

A new battery (directly from Apple) will be guarantied for a year and will give you a notebook to take with you (using an SSD instead of a HDD also gives you a few extra minutes in battery life.

CleanMyMac is not recommended! Instead install a new OS on the SSD and then using an external enclosure transfer the data via Migration Assistant. But always make sure you have a backup of your files. 

Honestly I am more of a fan of keeping things fresh and installing 3PP programs fresh too and manually dragging over your documents, pictures, music, etc.