I usually just find a topic that interests me then follow the rabbit hole to where it leads. If you want to get your feet wet on a liberty issue a good place to start is the history of free speech decisions.
Another thing to keep in mind is that there are manyJudges that were never SCOTUS, but also made notable decisions with regard to liberty issues. For example Learned Hand had many noteworthy things to say about the 1st Amendment
Learned Hand
Judge
Billings Learned Hand was a United States judge and judicial philosopher. He served on the United States District Court for the Southern District of New York and later the United States Court of Appeals for the Second Circuit. Wikipedia
Another thing to keep in mind is that there are manyJudges that were never SCOTUS, but also made notable decisions with regard to liberty issues. For example Learned Hand had many noteworthy things to say about the 1st Amendment