So a lot depends how much you want to move about and over how many days, plus I don’t know where you live.
IF you want to do South Wales you could do Cwmcarn, Afan Argoed, Brechfa with possibly some riding of natural stuff in Brecon.
North Wales you could do Marin trail, Llandegla, staying in Betwys-y-coed and (look at Glan Aber Hotel or bunk house) then move down to Coed-y-Brenin and spend a few days there saying at Cae Gwyn farm. If you wanted to head to Aberystwyth then do Nant-yr-Arian just make sure you are there for the kite feeding. Regrding Penmachno stay away! It doesn’t flow and in the height of the dry summer was living riding in a river bed, so depths of winter and it will be horrific. If you go North Wales you then have al the other options of hiking Snowdon and outdoor activities.