I am supportive. While gender and sexuality are incredibly intimate, private and sensitive subjects, I understand the necessity of LGBTQ+ persons to be vocal on these subjects given the centuries of oppression and ostracism they have experienced at the hands of families, schools, societies and so on. That's why I don't mind LGBTQ+ expression in open spaces, such as parades etc. It's hard to judge when you understand where somebody comes from and acknowledge the pain they have experienced.
It appears that every country that still opposes same-sex marriages and adoption is strongly motivated by the religious beliefs of its citizens. The way religion has shaped the image of family, gender and sexuality stands to this day. That being said, I support same-sex marriages, living together / having children without being married, adoption by homosexual families etc. It's all a personal choice and as long as the parties involved maintain their legal duties to the country, it shouldn't have a say in their private lives. Furthermore, it makes sense to me that two healthy-minded, mature individuals have the opportunity to give a home, family and love to a child (or children) that would otherwise spend their childhood in an orphanage.
Generally speaking, my motto is: live and let live.