We are going in early January and the options for evening entertainment look VERY sparse.
During Disneyland's "off season" the parks often do not have nighttime spectaculars on weeknights, only Fridays-Sundays. January falls during the "off season." They typically show World of Color nightly during the off season, including weeknights, but World of Color will be down for a refurbishment in January of 2024. Disneyland typically only releases show schedules 4-6 weeks in advance. This is, unfortunately, a compromise when going the Disneyland during a non-holiday or summer period - no guarantee of nighttime shows on weeknights. Shows are also often cancelled if windy (see below) or if raining (particularly fireworks). It really only rains at DL during the winter, with summer rain being very rare.
As for summer (June-July), Disneyland will be showing nightly entertainment of all shows. This means World of Color nightly, Fireworks nightly with projections, and Fantasmic nightly (as someone already noted). Yes, you can see the fireworks from the Fantasmic viewing location, but you will miss some of the castle effects that can only be seen from the hub/Main Street.
I do not recommend skipping Fantasmic at DL if you've seen it at WDW - the show is different and frankly better at DL. The caveat being that a "new" version of the show will be premiering at DL next May - we do not know yet what, if any, changes they will be making except for removal of the previous (and impressive) dragon animatronic. To see Fantasmic, you basically need to do a dining plan, which can be as simple as a to-go option from Hungry Bear. There is some limited standby, but they mostly did away with that after Covid. During the summer, Fantasmic will be shown nightly at 9:00 and 10:30 - the later show is always less crowded.
For World of Color, there is a "virtual queue" you can join on the DL app earlier in the day to secure your viewing spot. This is included in the price of admission (i.e. no additional cost to join the virtual queue). They typically show WOC at 9:00 and 10:15. DCA typically closes at 10:00 during the summer, with the show occurring slightly after closing. DL typically stays open until Midnight. DL fireworks are almost always at 9:30 nightly during the summer. DL fireworks do get cancelled often due to winds at higher elevations - so if you have a multi day trip try to see the fireworks as early as possible in case you have to try again. Fantasmic and World of Color are not cancelled as often due to winds.
One final note - if you are there on July 4th they sometimes show a special July 4th show on that one day only. I recommend seeing the typical (non-holiday) version if that's a choice you have to make, but see both if you can. They typically also add a "tag" for July 4th to World of Color but still show the regular version after.
Most importantly, check the DL schedule as your trip gets closer. About 6 weeks out for hours, and 4 weeks out for entertainment. The summer is usually very consistent with both hours and entertainment. DL is usually always open 8:00 - Midnight and DCA 8:00 - 10:00. WOC typically at the two times I noted above. Fantasmic and Fireworks as I noted earlier.
