The specific dates, locations and rules surrounding early and absentee voting vary by state, county and even municipality. First confirm that you are registered to vote and then contact your local election office or check their website for details about early and absentee voting.
Ballotpedia is great for learning about ballot measures and candidates. Check the left side bar for 2024 elections.
Yes ballotpedia is good, but I still wish it had more information about local (city, county) governments as well as judges. These ones are the hardest and most time consuming to research.
I also used https://www.ballotready.org/ it helps with some candidates, but looks like ballotpedia most of the time still has more info.
I found limited, but useful information from my state bar association about the judges running on my ballot.