なべで盛り上がる時期になりました
The season has come when/where
people get excited about hotpots.
peaple get excited about eating hotpots/hotpot meals.
～の時期になりましたは
The season has come
その後にwhen 以外に where が来ても同じ意味になります。
get excited の後の前置詞は about
なべは 鍋料理の意味で hotpots