You can also change the level of subdivision (or initially add subdivision surface modifier) with shortcuts. With the object selected, press Control + a number to change the level of viewport subdivision, even down to zero. Some caveats: if you do this while rendering in Cycles, Blender can get "irritated" lol and maybe crash or get laggy. In Eevee or Workbench, it's fine. I also wouldn't go much past 5 unless you want Blender to complain :). If you want to go higher than that then do it on the modifier panel.

Laurie