It is plural, but a pair of scissors is a singular object. It's confusing, I know, but no one talks about just one scissor.

English slang can be a little difficult to understand, but I'll try to help. Kotch - To kotch means to spend time with or "hang out" with a few friends. It usually refers to being lazy and wasting the day away. Drop dead - This is an insult and a way to tell someone to go away. By using this phrase, you're telling the person that you want them to die rather than continuing to talk to you. Off the heezie - To say that something is off the heezie means that it is incredible, exciting, or otherwise above average. It is a somewhat silly phrase and is usually used in a joking manner. Chillax - This just means to relax and have a good time. It is a friendly and very informal way to tell someone to calm down and enjoy themselves. I hope this helps. Feel free to contact me if you have any other questions.

To not be up to something simply means you don't have the energy of motivation to do it. For example, if you're feeling sick and someone asks you to go for a jog, you could say "I really don't feel up to that right now." Please feel free to contact me if you have any other questions.

I'd love to help out if you'd like.

You rarely use this phrase when talking about yourself. For example you wouldn't say "I want to get his goat." because it would sound stupid. You could say something like "He just want's to get your goat." or "It really get's my goat when that happens.". Remember, though, this is a very old phrase and if you used it now you would probably look silly. Try something more along the lines of "That really tics me off." or "That bugs me.". Those sound more modern and you'll look better saying it.