How many days off / rest days is highly individual.

Generally, do what your body is asking for. This is an intuitive sense that you will develop over time. Some people can exercise, stretch, roll every day and other people need a little bit more rest.

If you haven't been exercising much in the last few years or decades, start slow. Work out every other day. Do not rush or try to do the hardest version of any exercise. Give your body time to acclimate to the new things you're doing.

If you have plenty of experience with exercise and know your body well, you can work out more often. Just remember not to cripple yourself with soreness.

Overall, on this journey you get better and better at listening to what your body is really asking for. Sometimes it's asking for time to recover and re-model your tissues. Rest and don't force the issue as needed - it took many years for your body to get into its current state, so be patient as you gradually train it into a new state.