Yii framework community! There is a question: which additional things that are available for yii (it is about extensions, themes etc) should be used for similar marketplace to this one: https://zoptamo.com/uk/s-crossfit-c-uk , but launched on Yii? Maybe it is a stupid begginer question but there is a try to start learning yii and also an idea to build a site like this one added for example later, after learning this framework so any recommendations are appreciated.
No additional things needed. I don’t see anything extraordinary in that website.
Same answer with samdark.
However, I think you may want to use some extensions like WYSIWYG, file manager for admin.
Sorry, late reply :’) thanks for help, also extensions can be useful 
I used these for my catalog website:
karpoff/yii2-crop-image-upload for cropping category images
creocoder/yii2-nested-sets for making category lists
vova07/yii2-imperavi-widget description editor
voskobovich/yii2-many-many-behavior for item-category relation
himiklab/yii2-sitemap-module for XML sitemap