Fitness tracking beginner looking for new gadget

Hi all! I’m exploring options for a fitness tracker as I expand my fitness journey. My current workout schedule is reformer Pilates 2 times a week coupled with several long walks. My goal is to incorporate more cardio and strength training going forward, and I would love a device that sets / provides some form of fitness goals as I’m very goal oriented. I wear jewelry watches to work, so I’m not really looking for a daily fitness watch (unless it would still be accurate if I only wear it for work outs)! I’m not really sure where to begin, but information around heart rate and sleep would be great. Let me know your thoughts and happy to answer any questions to determine the right tracker!