Thank You Note

Hi Lisa,

How are you? I would like to provide some suggestions for your writing: 

(1) In your first sentence, you have two to-infinitives (i.e. "to read", "to correct). Infinitives are commonly used to express intentions. 

Therefore, you sentence actually is: ....who took their time to read my notebook entries and to correct my mistakes. However, English writers may often provide only as much information as is necessary to convey what they want to express, and this involves leaving out words or phrases so that the sentence does not sound overly formal and stilted, especially in speaking. This is known as Ellipsis. In your case, "to" is used once before "read", yet the reader knows that "to" also refers to "correct" because you used "and":

"....who took their time to read my notebook entries and to correct my mistakes."

Ellipsis is commonly used with coordinating conjunctions (e.g. and, but)

Another example:

I asked for a menu but I was given the bill instead! (not wrong, but it can be simplified)

I asked for a menu but was given the bill instead! (Ellipsis).

(2) We separate an introductory word or phrase from the rest of the sentence with a comma (,).

(e.g. Sadly, I am not able to... / Today, I just wanted to express... / In view of this, we shall discuss...)

(3) We use "in return" to describe our response to something that someone else has done for us.

Example: In return for your kindness, I promise that I will write a good review for you.

I hope this helps.

(your level is very good)

Thank You Note

Notes -

...to all who took their time to read (infinitive) my notebook entries and to correct (infinitive) my mistakes. 

or

...to all who read (simple past) my notebook entires and corrected (simple past) my mistakes.

I am very lucky to find this amazing community.  (spoken English)

or

I am very lucky to have found this amazing community.  (written English)