Hi @Yui, thank you for posting in the community! It sounds like you might be looking for keyboard shortcuts - you can find a list of our available shortcuts by navigating to File > Keyboard shortcuts (see example screenshot below). 

I hope this helps. Please let me know if this is not what you’re looking for, or if you have any questions! :) 

You can also find the shortcut keys for specific tools listed next to the tool when you hover over it or (in some cases) select it.
Lucidspark:

Lucidchart:

In Lucidspark, I use “V” and “H” to switch between selecting and panning most often (you can also right click to pan, but then I sometimes accidentally click things), and I could see “P” to switch to the pen for drawing being very useful for some people. What’s most useful for you will depend on what you use most often.