Creating your own products

How hard is it to create successful product on clickbank like the top products? Is that something worth to try?

Depends how much money and time you have. Its an investment and with every investment there are risks involved.
You can create 1 digital product, multiple digital products, membership feo, oto1, oto2, oto3...
Use clickfunnels for hosting digital products.
You can source physical products from China put a label and ship it.
You can sell supliments, this one is most lucrative.