could you help me proofread my English mistakes ? Topic Sentences
TOPIC: Your home town
In my opinion, to live in your home town bring you nice childhood remembrances.
You had had a good experience when you lived in your home town.
Living in your home town requires home security.
TOPIC: Word processors
Actually, there are very advanced word processors and they are useful.
Students at different levels study with word processors, even in the kindergarten.
Competition among word processors companies can be too hard.
TOPIC: Advertising
Advertising competition can be unfair many times.
There are some advertising not suitable for children.
A good advertising is very important to promote products.
TOPIC: Movies
Going to the movies while having time is a good idea.
There are certain kind of movies that children could not see.
Movies have changed the way entertain.
3 Answers
Your home town
In my opinion, to live in your home town bring you nice childhood remembrances.
In my opinion, to live/living in your home town brings back nice childhood memories.
You had had a good experience when you lived in your home town.
You had good experiences when you lived in your home town.
You do not need two "had"s. "Experience" should be plural, so "experiences".
Living in your home town requires home security.
Perfect grammar. However, I don't quite understand why it requires security.
Your sentence is structured perfectly. I just do not understand it. Can you clarify 
?
Word processors
Actually, there are very advanced word processors and they are useful.
Actually, there are very advanced and useful word processors.
You can use both adjectives (advanced and useful) before "word processors". Very good!
Students at different levels study with word processors, even in the kindergarten.
Students at different levels study with word processors, even in kindergarten.
Excellent. Just one correction: you do not need "the" before "kindergarten".
Competition among word processors companies can be too hard.
Competition among word processor companies can be very intense.
Advertising
Advertising competition can be unfair many times.
Hmmm...
This is okay, but it does not make much sense.
There are some advertising not suitable for children.
There are some advertisements not suitable for children.
Great! Just change "advertising" to "advertisements".
A good advertising is very important to promote products.
A good advertisement is very important when promoting products.
Movies
Going to the movies while having time is a good idea.
Going to the movies while having free time is a good idea.
Your original sentence is okay, but I suggest putting "free" in front of "time" to make free time.
There are certain kind of movies that children could not see.
There are certain kinds of movies that children should not see.
"Could" should be "should". Very good.
Movies have changed the way entertain.
Movies have changed the way people are entertained.
I added "people are entertained".
Your English has improved tremendously since the last time you posted. Well done!
Here are a few suggestions, I've tried not to change the content of your sentences just the grammar and word order 
TOPIC: Your home town
In my opinion, to live in your home town bring you nice childhood remembrances.
Suggestion: In my opinion, living in your home town brings to mind nice childhood memories.
NB: bring's' - remember that 's' when you conjugate most English verbs in the third person singular - I bring, you bring, it/he/she brings
You had had a good experience when you lived in your home town.
You would have had good experiences when you lived in your home town.
Living in your home town requires home security.
Living in your home town provides security.
TOPIC: Word processors
Actually, there are very advanced word processors and they are useful.
Actually, there are some quite advanced word processors which are very useful.
Students at different levels study with word processors, even in the kindergarten.
Students at all levels study using word processors, even those in kindergarten.
Competition among word processors companies can be too hard.
Competition among companies which produce word processors can be fierce.
TOPIC: Advertising
Advertising competition can be unfair many times.
Advertising compeition can be unfair at times.
There are some advertising not suitable for children.
Some forms of advertising are not suitable for children.
A good advertising is very important to promote products.
Good advertising is very important when it comes to promoting products.
TOPIC: Movies
Going to the movies while having time is a good idea.
Going to the movies as a way to have a good time is a great idea.
There are certain kind of movies that children could not see.
There are certain kinds of movies that children should be viewing.
Movies have changed the way entertain.
Movies have changed the way that we are entertained.
In my opinion, to live in your home town bring you nice childhood remembrances.
In my opinion, living in your home town brings back nice childhood memories.
You had had a good experience when you lived in your home town.
Not sure what you wanted here, it sounds weird to me.
Even in the kindergarten.
Even in kindergarten, "the" isn't correct.
Competition among word processors companies can be too hard.
Can be very intense. (as in 'muy') Can be too harsh. (as in 'demasiado')
Can be unfair many times.
Many times, advertising competition can be unfair.
There are some advertising not suitable for children.
There is some advertising that is not suitable for children.
Going to the movies while having time is a good idea.
When you have time, or while having a good time?
that children could not see.
SHOULD not see.
the way entertain.
The way we entertain.
