I have a fever.ひさしぶりにねつがでた

I have had a cold for the first time in a long period. It might be teething fever. I am trying to sleep early because my friend will come from a long distance to stay my room and I will be busy working tomorrow.

I have a fever.ひさしぶりにねつがでた

I have a cold for the first time in a long time (or: for the first time in awhile). This heat might be teething fever. I will try to sleep early because my friend will come from a long distance be travelling from a long distance to stay in my room and I will be busy working tomorrow.

Great job.

Just a comment: You can't say nor compare the sickness to "teething fever" unless you're describing an infant who is growing his or her teeth in.

I have a fever.

熱が出た。

I have a cold for the first time in awhile.

久しぶりに風邪を引いた。 

I will try to sleep early because my friend be travelling from a long distance to stay in my room and I will be busy working tomorrow.

友達が僕の部屋で過ごすために遠くから旅してくるし、明日の仕事は忙しいから、早めに眠ろう。