When your show uses the Serial episode release style, you can assign episodes a season and episode number. By default, an episode with season 1 and episode 2 will have its title formatted to look like this:
S1E2 - Podcast Title
This may be sufficient for you, but you can easily customize it. Visit your podcast dashboard and click Settings > Episode Formatting. From there, you can choose from either a compact format (the default), a verbose format, or define your own custom format.
Custom Formatting
You can define custom formatting by using the placeholders {season} and {episode} where the season and episode numbers would go, respectively. For example, Season {season}, Episode {episode}: would update titles to read Season 1, Episode 2: Episode Title.
If you're familiar with Python string formatting, you can use that to produce some interesting results. s{season:b}e{episode:b}>> will produce some fun binary like s10e1001>> Episode Title. Many other combinations and options are available. Aligning text with {season:<123}, {season:>123}, {season:^123}, and using a fill character with any of these options is not allowed.