:set mouse=a

And away you go. As you get more efficient at vim use you might find you want to turn that off again.

(and also without the colon in your vimrc file if you want it to stick)

In general yes, but there are still some cases where mouse is better than the equivalent keys. Mainly resizing splits (guess how many lines you want and then C-w <size>|, vs just dragging the divider).

:set ttymouse=sgr also makes it a lot smoother.