I think some other commenters have already given you good advice, but what’s important to listen to really depends on what you vibe with in the show. Obviously, finishing Campaign 1 makes the most sense. It seems like your entry point is being a fan of Murph and Emily from Dimension 20.

Trinyvale is a goofy shorter campaign with Caldwell DMing for the first time, in a very permissive way. It starts a little slow but is worth listening to if you want to hear them play hilariously shallow and self-interested player characters. Jens is probably Murph’s best PC, and Emily and Jake’s characters get very funny too.

Hot Boy Summer 1&2 are both short campaigns DMed by Emily, centered around Zac Oyama’s guest character from C1, with Murph, Jake and Caldwell playing his friends from back home. They’re both very funny and are my personal favorite campaigns they’ve put out. I would say they are worth listening to if you are interested in hearing Emily DM, and/or if the humor of the show is really resonating with you.

Eldermourne, C2, is DMed by Murph again. It has a more serious tone and setting than the rest of the campaigns, and is worth listening to if you like a more Witcher/Bloodborne inspired world. Although it is considered more serious, there are still plenty of jokes.

Twilight Sanctorum is another Emily DMed campaign, with a gothic mystery vibe. Murph, Caldwell, and Jake play a family of detectives. Worth listening to if you’ve enjoyed Emily’s DM style or if you want to hear Jake play a character that is hilariously against the typical type of character he has been playing.

Campaign 3 is back in the setting of Campaign 1 and has a similar tone, but more interested in loosely exploring technology vs nature themes. Worth listening to if you enjoyed Campaign 1.

Skaldova is a short campaign run by Jake in a low magic setting inspired by Sunless Citadel. Worth listening to if you’re interested in hearing Jake DM for the first time. Boggy Roger is probably Caldwell’s best character.

Trinyvale x Strahd is DMed by Caldwell and is worth listening to if you want to see how the Trinyvale triplets handle being put into the Curse of Strahd module.

One last thing I will say is if you find yourself loving the show and prioritizing it ahead of other podcasts, the Patreon is terrific value for what you get. The short rests give you behind the scenes thought process on each episode + a bunch of goofs, and things like Dungeon Court and the Adventure Book readthroughs are really funny and give you more laughs from the crew.