I worked as a concierge at a luxury condominium ofin Kyoto.

The previous sentence suggests that you still work there, so I'm switching this to the past tense. Of course, if you meant the opposite, you should switch it the other way around.

When I patrolled the roof of the condo, I found the place where the "Gonzan Nno Okuribi", which isthe famous for burning mountains inestival where the shapes of letters are burned onto mountains, is held every year.

My understanding is that particles in transliterated titles and names from Japanese aren't capitalized. Some random examples I found:
- 風に吹かれて = "Kaze ni Fukarete"
- 愛の季節 = "Ai no Kisetsu"
- 手紙 ～拝啓 十五の君へ～ = "Tegami (Haikei Jūgo no Kimi e)"
It's kind of like how in English, certain prepositions and articles won't be capitalized in titles.

It's because when I was a little, I uesed to watch that view every year with my father on the roof of the company where he worked.

So, I'd like to watch it again with him.

I hadused to have a part time job.

I am assuming this was a job you had in the past. “I had” is okay but “I used to have” flows better at the beginning of your text.

I worked as a concierge at a luxury condominium ofin Kyoto.

Again, assuming this was in the past and you don’t work there anymore. Condominium is correct but I’ve never actually heard it said. I’d call it an apartment building or condo.

When I patrolled the roof of the condo, I found the place where the "Gonzan No Okuribi", which is famous for burning mountains in the shapes of letters on mountains, is held every year.

So, I'd like to watch it again with him.

I had a part time job.

I'm assuming you still work there based on the rest of your post.

I worked as a concierge at a luxury condominium of Kyoto.

I'm assuming this is a past job based on the rest of your post being in past tense.

It's because when I was a little, I uesed to watch that view every year with my father on the roof of the company where he worked.

So, I'd like to watch it again with him.