Hello, I need help reading Momotarou and other easy books, but the online dictionaries don't have like 30% of the words I end up having to search for, and I don't want to assume something means something that it doesn't.

(I apologize for having to use romaji, I don't know where the buttons are for japanese keyboard)
I need help with:
mukashi mukashi arutokoroni

ookina momoga donburakoto nagaretekimashita.
mottekaette ojiisanto itadakimashou.

ojiisanga momowo kiroutosuruto
poonto otokonokoga tobidashimashita.
momokara umaretanode momotarouto yobou

momotarouwo sodaterukotonishimashita What does the "koto" mean?

Thank you for helping!

Quote from wotonito

mukashi mukashi arutokoroni

I'm not fluent in Japanese, and it's hard for me to figure things out without seeing the kanji/hiragana, but I think this like is saying something like "A long time ago in a certain place" tokoro meaning place.

poonto otokonokoga tobidashimashita

not sure about the poonto, but the rest I think is something like "a boy jumped out/appeared"

What online dictionaries are you using? I like this one.
I'd suggest you take off the participles (wo, ga, to, ni, etc) when searching, if you don't do that already.

Quote from chibilin

Quote from wotonito

mukashi mukashi arutokoroni

I'm not fluent in Japanese, and it's hard for me to figure things out without seeing the kanji/hiragana, but I think this like is saying something like "A long time ago in a certain place" tokoro meaning place.

poonto otokonokoga tobidashimashita

not sure about the poonto, but the rest I think is something like "a boy jumped out/appeared"

What online dictionaries are you using? I like this one.
I'd suggest you take off the participles (wo, ga, to, ni, etc) when searching, if you don't do that already.

I tried using that one but I still couldn't find the words I was looking for, that was the last one I tried before I decided to try asking you guys, and I do take off the wo ga to ni things when searching.
Thank you for helping 😎

Also, it was all written in hiragana, so I couldn't give you the kanji if I wanted to.