Many elderly people have a hard time withdrawal from ATMs.

Better say: Many elderly people have a hard time withdrawing from ATMs.

You never know why this computer is floating an error message. --**Correct sentence~ ^^ 

I saw him with a cat the other day. --*Correct sentence~ ^^ 

Actually, he gave money to university to enter there.

Better say: Actually, he paid to attend university.

The sensor's activated, we need to be more careful. --*Correct sentence~ ^^ 

You must not assume that he is a suspector.

Better say: You must not assume that he is a suspect. 

The call got dropped third times. 

Better say: The call was dropped three times.

I hope every single my team members gethers at my seat right away.

Better say: I hope that all of my team mates arrive at my seat right away.

You'll need an order number if you want to pull up your order information. --*Correct sentence~ ^^ 

I couldn't pull out money because there weren't any ATMs.--*Correct sentence~ ^^ 

You can make a new fund account which have a minimum loss.

Better say: You can create a new fund account with a minimal loss.