I went hiking at the mountain near by my house and roding bicycle at Han River last weekend. --> I went hiking at the mountain near by my house and rode my bicycle at the Han River last weekend.

Weather was very nice.  So there was a lot of people at Han River.  --> The weather was very nice, so there were a lot of people at the Han River.

=> Corrected: The sentences are corrected grammatically.​

Put your brain to work. --> Use your head.

=> This sentence is okay. This is another way of saying it.​

The Cat want to be let out. --> The cat wants to be let out.

=> Corrected: The sentence is corrected grammatically.​

Can I pay it by credit card? => Corrected​ punctuation.​