Help - continuous tense

I have questions about the continous tense:

1 - I'm thinking about going to Miami.

2 - They are thinking about coming to China

3 - She was interested in buying a new printer

Why do I use 2 verbs in continuous tense in the first and second sentences?

And why do I use "buying" and not "she was interested in buy a new printer"?

IS THIS SENTENCE RIGHT?

Is this sentence correct?

"I must have to take my kids to school" 

Right out my untrimmed chest What does it mean "untrimmed chest"?

IS THIS SENTENCE OK?

"I'm without time to prepare my food"

Is this sentence correct?

HANDMADE? HELPPPP

In "Shape of you" by Ed Sheeran, we can find the sentence "your love was handmade for..."

Is it correct? Was + verb in the past?

Can you explain me? 

LEAD PENCIL VERSUS MECHANICAL PENCIL - VOCABULARY

Whats is the difference between "lead pencil" and "mechanical pencil"?

English Native Speakers Any english native speaker who would like to help me improve my english skills?

MAS e MAIS

I want to help you with portuguese

HI EVERYONE

Me and my boyfriend are creating a new blog to help you with portuguese. There are only 3 posts now, but you can make questions, so we can write about what you really want. If you interested, I would like to have your feedback.

http://mundialmente.com.br/