BuddyPress.org

To start off, you’d have to change template tags e.g. change default link to Member Activity Page to Member Profile page

change
<a href="<?php bp_member_permalink(); ?>"><?php bp_member_avatar(); ?></a>
to
<a href=”<?php echo bp_loggedin_user_domain(); ?>”><?php bp_member_avatar(); ?></a>

change
<a href="<?php bp_member_permalink(); ?>"><?php bp_member_name(); ?></a>
to
<a href=”<?php echo bp_loggedin_user_domain(); ?>”><?php bp_member_name(); ?></a>

Instead of the template change suggested above, it works better to add the following

/* set default BP to profile page instead of activity page */
define( 'BP_DEFAULT_COMPONENT', 'profile' );

in your wp-content/plugins/bp-custom.php file (create that file if it does not exist – see https://codex.buddypress.org/plugindev/bp-custom-php/ for more about that file).