I simply have a question about love and boasting. I know that 1 Corinthians 13 says love is not boastful. Would you consider it boastful if I told someone that I loved them, despite our views and opinions not being similar? (For example, when it comes to abortion). If I were to misunderstand love, would it be sinful?

No. Telling someone you love them even if your views are not similar is not boastful. Our love for people goes beyond agreement on issues and opinions.