[General] At first, it was

[Anil Giria]

At first, it was difficult for me to adjust and I couldn't fit in.

At first, I found it difficult to adjust and I couldn't fit in.

Are these sentences OK and do they convey the same meaning?

 

[Rover_KE]

Yes and yes.

 

[Anil Giria]

At first, it was difficult for me to adjust and I couldn't fit in.

At first, I found it difficult to adjust and I couldn't fit in.

Are these sentences OK and do they convey the same meaning?

Is using "they" correct?

 

[Tarheel]

Yes, there are two sentences, so "they" is correct.