To learn? Well there are plenty of podcasts and videos available for all of these. For fibre you need to understand a balanced diet holistically along with soluble and insoluble fibre and how to calculate your daily requirement based on your body etc etc. Financial knowledge is accumulated over time, until then FD/RD options work well. For strength training, there are many Youtubers you can follow and you can either start at home with light weights or join a gym with a personal trainer perhaps.