If you can use exclamatory words naturally in other languages, you seem to be good at speaking the language. When I was in Canada, I tried to use exclamatory words, but it was hard to say those words naturally without thinking.
Let’s look at useful exclamatory words in Japanese. Today is “Otto”. This is written as “おっと” in Hiragana and pronunced as "O-ttoh". “Otto” is used when you have fallen, dropped something, been surprised, made a small mistake. This is used just like “Oops” in English.
For example, “Oops, I dropped a pen” can be “おっと、ペンをおとした(O-ttoh, Pen wo Otoshita.”
*"O-ttoh, hold the unicycle tightly!"