Step 1
Install =lein= from the url below check that the =lein= command works from the command line.
https://leiningen.org/

Step 2
Install clojure and make sure =clj= and =clojure= command work from the command line.
https://clojure.org/guides/getting_started

Step 3
Make sure you have java installed, even if not using java and are targeting javascript some of the tools use this eco system.

Step 4
Download an IDE visual studio with calva plugin is recommended and very capable CIDER is also very popular but has a much steeper learning curve if your not familiar with emacs I don't recommend learning both at the same time.
https://github.com/BetterThanTomorrow/calva

Step 5
Check you can jack in to a simple project.

#+BEGIN_SRC sh
git clone https://github.com/bhauman/flappy-bird-demo-new.git
#+END_SRC

Try running it at the command line first if that works then try connecting.

#+BEGIN_SRC sh
clj -A:build
#+END_SRC

Then try connecting from your IDE

As an example.
https://www.youtube.com/watch?v=a2vRDYXDAug