I like to know if I want to build small webshops is Magento beter than Dupal?
2-the same question I ask for wordpress with woocommerce plug in is magento beter ?
3- is there forums who can help me in the way when I get problems while I am learning and building websites with magento?
Personally I wouldn’t recommend learning magento to build small webshops (obviously depending on your definition of “small”). On the other hand I wouldn’t recommend Drupal either for various reasons. I’d suggest you’d look into prestashop. Even though woocommerce can be a great userfriendly platform, wordpress never had e-commerce as a primairy goal and prestashop did, so in terms of software architecture I think prestashop would be a better fit. Magento has a steep learning curve, and for small webshops it would cost a lot to maintain. So i’d suggest looking into either woocommerce or prestashop (or opencart or any other simpeler e-commerce platform, based on your needs, and specialisations).
Dutchento is a Dutch Magento community, so even though i’d welcome you to join us, I think we’re not the right fit for your needs. If you’re really new to all this I’d suggest taking a udemy course for the platform you choose ;).