You don't have to pay for me. Let's go dutch today. 
مجبور نیستی پولی به من بدی ، امروز هرکی دُنگ خودشو میده !
I have nothing to do. I'm bored to death. 
کاری ندارم انجام بدم . خیلی کسل هستم .
bored to death = extremely bored
خیلی خسته کننده و کسل
You've got to be kidding me. I'm 30 years old! 
داری باهام شوخی میکنی ! من سی سالمه !
I'm sick and tired of eating the same thing for lunch everyday. 
هرروز ناهار یه چیز بخورم حالم بد میشه.
Let's call it a day. I'm too tired to continue working. 
برای انجام بقیه کار خیلی خستم ، بیا کارو تعطیل کنیم.
call it a day = to decide or agree to stop doing sth,
Will you please stop doing that? It's getting on my nerves. 
میشه اون کارو انجام ندید ؟ داره عصبیم میکنه !
I should be more active and less of a couch potato. 
باید کمتر جلوی تلویزیون لم بدم و فعال تر باشم.
couch potato = a person who spends a lot of time sitting and watching TV.
You read my mind. That's exactly what I was thinking too. 
فکرمو خوندی ! این دقیقا همون چیزی بود که داشتم بهش فکر میکردم.
What a gloomy day. It makes me feel blue. 
چه روز غم انگیزی . منو دلگیرو افسرده میکنه.
I got into a small accident. It was just a fender-bender. 
یه تصادف کوچیک ماشین داشتم ، یه تصادف جزعی بود.
There's nothing to be scared of. Don't be a chicken. 
ترسو نباش.چیزی برای ترسیدن نیست.
Make up your mind, we don't have much time. 
زمان زیادی نداریم ، تصمیمتو بگیر.
make up one's mind = Make a decision; decide
I actually prefer going dutch because I don't want to feel in debt to anyone. 
درواقع ترجیح میدم دنگی حساب کنیم ، نمیخوام حس کنم به کسی بدهکارم.