I hadve read a few chapters of Doctor Dolittle novel.

Both had / have are ok, but had is for telling a story in the past. Have is for telling a story that is going on right now.

I usually googles the imaginary animals because I didn't know that they are not real animals.

I google - he googles

Reading novels is more interesting than reading newspapers sometimes.

Someone told me that I should knowlearn how to think in eEnglish.

That person said that I am thinking in my mother tongue and translating my mother language into eEnglish rather than thinking in eEnglish in first place.

So, that person suggested for me to read like hell along with other practices.

I hadve read a few chapters of Doctor Dolittle novel.

or just "I read..."

I am mainly reading this forto improvinge my eEnglish skills.

could also say "mostly" instead of "mainly." That might be more natural but this is not a problem

I usually googles the imaginary animals because I didn't know that they are not real animals.

Reading novels is more interesting than reading newspapers sometimes.

Someone told me that I should know how to think in eEnglish.

That person said that I am thinking in my mother tongue and translating my mother latonguage into eEnglish rather than thinking in eEnglish in first place.

So, that person suggested me tothat I read like hellcrazy along with other practices.

You are right that "like Hell" means "a lot" in some circumstances, but not this one. "Like crazy" is a better fit for "a lot" in this sentence.
"suggested that I" could also be "suggested to me to"

Reading a nNovel.

Title capitalization rules

I had read a few chapters of the novel "Doctor Dolittle novel."

I am mainly reading this forto improvinge my eEnglish skills.

English is always capitalized

I usually gGoogles the imaginary animals because I didn't know thatrealized they are not real animals.

Google is a name, so is capitalized

Reading novels is more interesting than reading newspapers sometimes.

Someone told me that I should know how to think in eEnglish.

That person said that I am thinking in my mother tongue and translating my mother language into eEnglish rather than thinking in eEnglish in the first place.