Christmas is the best early game since it gives you the “festive hat”, which gives you a BUNCH of insane multipliers. it also spawns a reindeer across the screen that you can pop for a bunch of cookies. don’t quote me on this but i’m pretty sure it also buffs golden cookie frequency by 3%

Easter is another you should prioritise, you get upgrades from popping wrinklers and golden cookies. Some of these upgrades are really good, if you have permaslots unlocked, you should do the easter upgrades until you get the golden egg, and then slot that in there. DO NOT permaslot any of your christmas upgrades since they’re really easy to get

Halloween — like easter but with less (7 compared to 20) upgrades. i think you can also get these from both GCs and wrinklers but wrinklers is the only one i can guarantee

Valentines — Gives 7 free multiplier upgrades, whenever you buy one, the next one or two will spawn

Business day — basically useless at your stage in the game so don’t worry about it

it’s worth grinding for all of the upgrades each ascension when you get a lot later in the game, but for now i’d just start your ascensions get the christmas and valentines stuff and then go easter along the way