I've recently started playing a play by post campaign as a player. It has occurred to me that Dragonborn Paladins are popular characters and so are a Tiefling Warlocks.What kind of challenges would I face with playing one of those race/class combo. I normally play half elf or human but would be open to try one of those . Pros and cons please. I used to play 3.5e all the time so 5th is new to me kinda
The only "problems" with these races are that they are considered "uncommon". All this means is that you are easily identified in a crowd, due to being a 6-foot tall lizard man, or a demonic creature. For the most part, the only disadvantage you might come across is that people might be wary of you in an interaction.
As for advantages, the Dragonborn has a breath weapon, which varies depending on your ancestry, and the Tiefling has access to a range of spells as the character levels up, such as Thaumaturgy and Hellish Rebuke. In addition, Tieflings get fire resistance as a racial trait and fire damage is one of the most common elemental damages.
You can discover more by reading the PHB; all of this is covered in the book, as well as all other playable races.