Welcome to the best way to enjoy World of Warcraft!
My first point of advice would be to check out this thread:
There really is no better place to get you up to speed on everything in regards to RPing, including terms, types of RP, useful addons, and so forth.
Beyond that, I’ve got no advice specific to paladin or squire RP, but I will say this: Be ready to hang around Stormwind City a lot, reading TRP profiles and looking for people who seem like they’ll either fit in well with paladin squire RP, or who just seem like interesting characters for your character to intersect with. Approach them, either with an IC introduction or with an OOC message about what you’re looking for in RP.
You may need to set some basics up about your character first: Which kingdom are they from? What family do they have? What is their relationship like with their family? If they aren’t a resident of Stormwind, why are they in Stormwind? When they aren’t training as a paladin, what are they doing? How do they feel about having Man’ari, Dark Irons, Death Knights, Demon Hunters, and other more “problematic” people officially welcomed into the Alliance? How do they feel about the Horde? Once you have a decent idea who your character is, you’ll find it easier to get into casual conversations and stay in character and to interact with others.
My advice is to keep things simple for starters and let the connections and relationships grow organically through RP. This has been my method in the last few months and I’ve gained about a half-dozen RP contacts that have really clicked, both with Dloin and with each other. But, I’m also an RP veteran so I already had a very strong idea of who Dloin was and what sort of characters would work with him.
Finally, if you’re using TRP (which you should), mark your profile as new to RP, and look for profiles with the green flag - this indicates people who are veteran RPers and are willing to help newbies learn the ropes.
And finally for real, Dloin is a blacksmith who has forged weapons for paladins in the past, and he’s currently involved in a relationship with a paladin and has worked closely with paladins over the years. He himself has a lot of baggage with the Light, but I’m always looking for new contacts. Feel free to reach out in game we can set something up!