Hello Sulpai
I am a graphic designer who often hires illustrators and if you want to pursue illustration as a full time carreer I would advise to consider looking into editorial illustration as well. Many organizations need talent to illustrate their research publications. Do be intentional on building a porfolio targeted to an industry and topics of interest, even start with fictional proyects to build it up. Also I would advise you to take a look at Behance to see what other illustrators are doing, that may spark some ideas.