Both are fine, and the part in parentheses is also good. You can also introduce the topic by making a statement: You asked about my English, so let me tell you ... If you're answering several questions, you could also do something like this: OK, let me answer your questions for you! First, my English experience is ..... Next, ..... You also asked about ...... Or even just start each answer with a key word: English - I started .... Football - my favourite team ... Food - I love ...

I agree with Tom, both are fine. I would be more likely to use your first example, especially in a casual conversation. The second example is great for more formal or professional speech.

"To you answer your question, yes, i've been studying english for a long time"

Both of those sound quite natural, although "with regard to" is more grammatically accurate than "with regards to". Another alternative is "in regard to (your question about) my English".