Street Fighter

Give her a try! She's the perfect balance of accessibility and complexity IMO. At a very basic level you can stick to her normals in neutral and combo into lightning kicks for simple combos, with a focus on spacing. Her normals are some of the best in the game, and she has really fast walk speed for baiting. Once you get that down you can add in her charge inputs, including spinning bird kick combos for a bit more damage and better oki, and then you have her stance and crazy combo potential later on. She's not intimidating to learn at all though compared to other technical fighting game characters. Just sprinkle in some more stuff once you feel ready for it.