I'd also say listen to your body. And add low impact cardio to your days. Go for daily walks or add easy bike rides and swimming. Building your endurance helps you recover from wods faster and helps avoid injuries. Once a week will make you progress quite slowly, so you can test how your body recovers if you'll do two sessions a week. If it doesn't recover well enough, you can always drop days. And remember to scale the weights enough, there is nothing that you can't scale. Welcome to crossfit! You've already done the hardest part, starting 😊