>> Yes, you are right that life originally started as asexual reproduction and sexual reproduction appeared later
No, that's a hot research topic.
E.g. a popular hypothesis is than in an RNA world very early and simple organisms had inefficient metabolism and error-prone genetic copy. They didn't have enough energy to sustain a backup of their genetic information, RNA is not very stable, etc. So the only way to keep functioning was to constantly mate with other organisms and exchange good replacements for broken genes.
No, that's a hot research topic.
E.g. a popular hypothesis is than in an RNA world very early and simple organisms had inefficient metabolism and error-prone genetic copy. They didn't have enough energy to sustain a backup of their genetic information, RNA is not very stable, etc. So the only way to keep functioning was to constantly mate with other organisms and exchange good replacements for broken genes.