What is this? and What is that? In polish is "Co to jest?"

Cambridge english Writing and Improve I started practising English by using Cambridge English Write & Improve. There is a few feedback but I do not know to reach B1 level. My level is always A2. (But my actual English level is B1, I believe) So here is Theme of Writing. You recently went on a trip for two weeks. While you were away, your friend, Ken, looked after your home. When you return, you decide to write an email to Ken. In the email: thank Ken for helping you tell Ken what you did on your trip suggest a time to meet Ken. Write about 90 words. And my writing sentences are... Hi. Ken. Thank you for looking after my house for two weeks. My trip was so nice. I started my journey from Pais and moved to Germany and Czech. I am back in Japan from Poland. I visited some friend in each country and hanged up. There are very beautiful places, but most I impressed places is Prague Castle. That castle is in Prague, Czech. That started building in AD 870 years. Which means the oldest part of the castle is over 1000 years old. I bought some souvenir for you. If you are free next Monday morning, let's hang up.

The script of introduce my self. I thought It's better to prepare some script to introducing my self because We often do that. So I made some sentences for that. Please correct that if there is error and please rewrite more natural expression. And if you have advice like you should add more information and so on, please teach me. It will be really helpful! Name/Gender/Age My name is Akari. I'm 22 years old. I'm a University Student and I'm studying Architecture. I live in Fukushima with my family. My family is grandparents, my parents and brother, six of us. My brother is 20 years old. He is a university student as well. We have a dog, dachshund. Her name is May. She likes eating. About Hobby  My hobby is watching TV dramas. My favourite TV drama is Game of Thorne. I like that drama because that script, clothing and set of every scene have so much detail about that. But the simple reason I like that, I just addicted to keeping watch. About Food what I like  I have three favourite food. I can't decide which one is best. That three foods are Potato, Chocolate and Macaroon. I usually eat potato as french fry and Potato pancake. If you cook Potato Pancake, I recommend you add onions. It is going to be tastier! About food what I don't like I don't like Celery. There is no fault for Celery but I am not good at ? that smell. If I eat that the flavour spread all around my nose and I feel terrible. About my hometown My hometown is in the north of Fukushima and it is called Kunimi. The population is nine thousand people. Thirty-six per cent of people are over sixty-five years old. This town is famous for Preach. We can eat fresh Preach in summer. Thank a lot

Do you have any idea to use italki effectively?

Hi, I'm new here.

Do you have any idea to use this site effectively?

Actually, I'm not sure how to use this. 

Thank you!