As a beginner rider, it's generally recommended to start with a motorcycle that is more manageable and forgiving in terms of power and handling. Out of the options you provided, the 2017 Yamaha YZF-R3 would likely be the most suitable choice for a first bike. Here's a breakdown of the four options:
2016 KTM RC390: The KTM RC390 is a lightweight sportbike known for its aggressive styling and performance. While it may be tempting due to its sporty nature, it has a relatively powerful engine (373cc) and aggressive riding position, which might not be ideal for a novice rider.
2017 Yamaha YZF-R3: The Yamaha YZF-R3 is a popular choice among beginner riders. It features a more manageable engine (321cc) and a comfortable riding position. The R3 offers a good balance of power, handling, and affordability, making it a suitable option for gaining experience and building confidence.
2004 Triumph Daytona: The Triumph Daytona is a sportbike with a larger engine (typically around 600cc or more). As an older model, it might have a more aggressive riding position and potentially higher maintenance requirements. Sportbikes of this nature are generally better suited for more experienced riders.
2003 Suzuki GSX-R: The Suzuki GSX-R is a high-performance sportbike with a powerful engine. It's not recommended for beginners due to its aggressive nature, high power output, and demanding handling characteristics.
When starting out, it's essential to prioritize safety and choose a motorcycle that you can handle comfortably while developing your riding skills. Consider factors such as engine size, weight, riding position, and ease of maintenance. Additionally, taking a motorcycle safety course and practicing in a controlled environment can significantly contribute to your learning process.