Hello I'm new to the game and I've noticed that there's some difference in content with the PC version, for example, the class. Will BD Mobile get the same content as the PC version regarding class ascension and awakening? Thank you

Yes eventually, but in its own way. For example striker has an ascension and awakening on PC, on mobile he only has an ascension. The same goes for shai. Content will be slightly different to take in account that its a mobile platform. You have to remember BDO started in 2014, BDM only just released for global in 2020.