My MacBook is getting slow and is hanging a lot. how Can I upgrade it

You are like hitting a few different issues!

• Max your RAM to 16GB if its not already
• Replace your HDD for a SSD, don’t forget to replace the HDD SATA cable as these often need to be replaced Your Hard Drive Cable Is A Ticking Time Bomb if you have already replaced your HDD for a SSD its likely your cable was the older version which can’t sustain the heaver data flows from your SSD.

Lastly I recommend you leave 1/4 to 1/3 of the drive unused! This allows your OS and apps to have some breathing room. With SSD’s is more important so wear leveling can take place effectively.