'How can I personally see you' or 'How can I see you personally' are better. There is no function for the preposition 'to' in this sentence.

"Personally, I try to avoid using the word, 'personally' in sentences".

Personally, I don't think there is anything wrong with it. Personally, I believe I am correct.

You don't contact them. If you know someone personally, then you contact them personally.

Yes, a comma should come after personally. Example:

Personally, I find this website very helpful.