I don't think you need to follow fashion as much as you need to develop your own style, which means knowing who you are and what image you want to project. If you follow fashion slavishly, you'll be at the mercy of every new trend, from cold shoulders to dust ruffles, whether it does anything for you or not.
When I was your age a book which really helped me get out of a style rut and transition from university to the workplace was Simple Isn't Easy by Olivia Goldsmith and Amy Fine Collins. Although it's over 20 years old, it was about style rather than fashion so hasn't dated much and I would still recommend it - except it's long out of print and second-hand copies are super expensive. But other posters may be able to suggest something similar.
It might help to follow the style of actresses/celebrities in their 20s - particularly their street style, which is usually far more accessible than the red carpet. When you see a photo you love, try to copy it and by a process of trial and error, you'll discover what is really "you." It helps if you are emulating someone who is similar to your body type/colouring.
Also, try reading interviews with costume designers who have worked on recent films set in the present day. On screen, every single aspect of an outfit, from lipstick to jewellery, is carefully selected to tell the audience something about a character. When you understand more about how that is done, you understand the messages you are sending with your own choices, and can adjust as you see fit.
For example, that top could come over as frumpy/ageing because it combines florals (feminine, sweet, unthreatening) with a loose cut (forgiving for matronly figures). To counteract that, you'd need to combine it with a body-conscious bottom half and younger accessories, as PP have said. Yes, it's something Mary Berry would wear, so you need to team it (hate that phrase! sorry) with something she wouldn't wear! MB would probably accessorize this with chunky pearls or a scarf and court shoes - you could look at e.g. Glamour or Cosmopolitan for ideas for accessories which are more age-appropriate. Try red lipstick (rather than the nude the model is wearing or a nice safe berry stain).