Hi there! I have an old and slow laptop too!
Here are some tips you can do to make it faster!
1. Clean up - Remove useless files
2.Disable useless apps on startup manager.
3. On whatever browser you have, you can try to disable wallpaper, animations.
Please, try watching some youtube tutorials on how to boost your pc. I learned all these from them! (and more)
Pc cleaner software? Don't download CCleaner, try Glary Utilities! That's what I use and it's really useful. Oh and make sure to go to settings for disk clean up and uncheck cookies. You might log off from websites.