Concert in Barclays Center Question

I have a concert coming up soon in Barclay, and I'm going alone. I bought the ticket presale, and they only had a limited side-view section in row 226, with about 20s left. How bad is that seat? I'm not a die-hard fan, but I love hearing the artist's songs and singing along live (also my first-ever concert). I can exchange (wait, nvm I think it's too late to exchange) for section 210 for $60 more. Or another way is I was thinking if I can ask the box office on the day if I can exchange/upgrade. Is that common? Someone also told me to just move sections or move within my sections to empty seats. Is that allowed, or are they strict on it?