Question
If a Jew does something during the three weeks that is forbidden during that time (e.g. listening to music, getting a haircut), have they actually sinned according to Halacha? Is it a sin, just like violating Shabbos or eating treif are sins? Would the term ‘avera’ be applied to such an action? Is the intentional, willful violator of the three weeks restrictions required to make atonement?

Question
Dear Rabbi, Hi, I have been studying Judaism for a while now. After much deliberation I really want to covert to Judaism, specifically Modern Orthodox Judaism. I have found a synagogue in my area but I am confused in whether I should approach a Rabbi there or a Beth Din in my area for a halacha conversion. Sorry if this is a silly question, I couldn't find a straight answer straight away and I wanted to ask a trusted and knowledgeable source. Thank you so much.

Question
The Torah makes clear the punishment for failure to fast on Yom Kippur - kareis. Is there any punishment for refusing to fast on one of the other five fast days when one has no medical reason to avoid it?