Yes, this may be something you can do yourself, but first you need to determine whether RAM is actually the problem and whether your computer’s RAM can be upgraded.
Deleting files usually doesn’t increase RAM. That frees storage space (SSD/hard drive), which is different from memory.
So if you mean you are running low on space you might need to upgrade to a bigger SSD or add an external drive or use cloud drive. But if you computer is running slow in general then you might need RAM. Can you please clarify that first?