In the moments where Jesus connected deep with the disciples, Jesus gave them a big command as well as various promises. Jesus said such things so that "[His] joy may remain in [them]" and that "[their] joy may be full" (15:11). In particular, the commands are meant to ensure that people do not screw themselves over, allowing them to experience full joy from Jesus, even in the worst scenarios.
Speaking of command, Jesus then proclaims to the disciples an important commandment -- "love one another" like what Jesus did to the disciples (15:12). In particular, Jesus talked about how the greatest love is laying down one's life for friends (15:13) -- kinda like what Jesus would later do. In fact, Jesus referred to the disciples as "friends" rather than servants since they know what the Father wants -- loving one another (15:14-15).
To close off the command, Jesus used another limited negative to talk about how Jesus chose the disciples and appointed the disciples to "go and bear fruit" (15:16). Jesus's care and commitment is done before the disciples even chose Jesus because Jesus knew the disciples. Thus, when the disciples ask in Jesus's character (AKA "in [His] name"), the Father would give them that (15:16).
In the conversation, Jesus established love as one of the most important calls in Scripture. Love is the reason why Jesus died to take on our penalty for our behalf.