Here are 10 things that a beginner triathlete should watch out for:

1. Overuse injuries: Make sure to cross-train and vary your workouts to reduce the risk of overuse injuries.
2. Dehydration: Stay hydrated by drinking plenty of fluids, especially during hot weather or long workouts.
3. Poor nutrition: Make sure to fuel your body properly with a balanced diet that includes enough carbohydrates, protein, and healthy fats.
4. Skipping recovery: Allow your body to recover between workouts by getting enough sleep, stretching, and using recovery tools like foam rollers and massage.
5. Neglecting strength training: Incorporate strength training exercises into your routine to improve your overall fitness and help prevent injuries.
6. Not following a training plan: Follow a structured training plan that gradually increases your volume and intensity to avoid burnout and overtraining.
7. Not practicing transitions: Make sure to practice transitioning between the swim, bike, and run portions of the race to become efficient and smooth.
8. Not testing equipment: Test out all of your equipment during training to make sure it is in good working order and to get comfortable using it.
9. Not practicing race nutrition: Experiment with different fueling strategies during training to find what works best for you during the race.
10. Not pacing yourself: Practice pacing during training to make sure you have enough energy to finish the race strong.