A start would be to follow the installation guides!
What have you tried thus far?
Buddypress is as simple as downloading the plugin to your plugin directory and in the dashboard enabling the plugin. You can download the plugin from within WP!
Also, read the readme.txt file that comes with the BuddyPress download package. It tells you everything you need to know. Of course, if you’re using the autoinstall feature from the plugin browser in WP’s backend, then you may not even know about the readme.txt file.
imho it’s always better or advisable to download/ upload manually – never quite trust things that are automated