I think everyone begins their journey as a designer exploring pre-existing typefaces. For a long time fonts were able to fill my design needs, yet now I rarely use them.
Part of growing as a designer is finding what works best for you and your clients. The exploring stage to define your own unique style is crucial to both business and your ability to sell your personality in your work. If you use Comic Sans (a designers worst nightmare) clients, and the design community, are likely to dismiss your abilities; use a typeface like Helvetica and suddenly you’re on a path to success, commanding respect within the community.
However, typefaces do not necessarily provide growth in your skills once you have defined your style. Personally I use a lot of textures in my work to capture the vintage, worn, and decayed look - all of which I established using pre-existing fonts. But when you come across websites like Dribbble or Smashing Magazine, you realise typography far exceeds the realm of serif and sans serif fonts. There is a whole other branch on the metaphorical typography olive tree known as hand lettering.
There are many ways to achieve your desired hand drawn look - sketch and render in illustrator using either the pen tool and/or live trace, or use a graphics tablet. Each method varies, and each method will give a slightly different outcome. It’s important to find which method works best for you. I use a combination of sketching, scanning, live trace and a graphics tablet depending on the project. It requires time and effort, but the results are always worthwhile.
If pre-existing fonts work best for you and your clients, stick to what you know. But if on the off chance you want to mix things up, try hand lettering - many new avenues will open up because of it.