If Tableau and Qlik are out of line & starting with a marketing dashboard is more than sufficient for you, definitly check out Supermetrics.
Every time I want to learn a skill online I’ll check out what the actual builder of the product is offering. Chances are they have the widest range. Don’t forget to YouTube your needs or get more from udemy.com to stay on top. 🙂
If you ever wonder how your website is doing category wise & on a global ranking position, or just towards your competitors, definitely check out similarweb.com & hook it up.