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.

CleanMyMac and other programs like it are often a bit too aggressive in what they "clean" and how they do it. A utility like Onyx will clean the HD of unnecessary items and do some maintenance without going to the extremes that CleanMyMac does.

I agree with Andrew, the SSD is the first consideration followed (VERY) closely by RAM. Those two things will give you the best speedup.

Install the O/S fresh on the SSD and use the Migration Assistant to install just user files. Install your apps fresh from install media (downloads, CDs, etc). That should give you the best bang for you buck as there are likely things that apps installed clogging things up.