If you are just looking for an easy start that combines everying similar to other messengers, this might be the right category to look at.
Quicksy is a user-focused offer for Android by the developer of the Conversations App that allows you to easily create a Jabber account based on your mobile phone number. Other Quicksy users in your phone's contact list will be recognized by the app. Learn more about it on their website. You can register from within the Quicksy app:
Soon Quicksy will also be supported by Monal for iOS
Movim is an all-in-one server and web-client that works well in desktop & mobile browsers. You can easily sign up to a Movim instance and use it on all your devices. A unique feature of Movim is that it can also be used for blogging. Of course Movim is compatible with other XMPP clients.
Snikket is a project started by one of the Prosody developers to provide a unified app experience including user friendly server hosting. It is ideal if you are looking for a small server to share with friends and family. You can either ask them to host the server for you or host it yourself.