git cloneor whatever to ~/common-lisp
Then assuming you have a REPL up
(asdf:clear-source-registry)
(asdf:load-system :drakma)Drakma is used as an example but I would actually encourage you to try it. It surprisingly has many dependencies because of the dependencies of it's dependencies.
You'll get yelled at about what dependency you're missing so you hunt it down, drop into ~/common-lisp again and repeat the asdf commands. Tedious.
Guix is a good suggestion, Nyxt does this, as an example of a larger CL project. Writing Guix packages is easy too so if you don't find a CL library supported, do the world a favor and write a Guix package so we have a bit less misery.