WooCommerce is a plugin for Wordpress so I don't even know why you have Wordpress seperately in the poll, makes no sense.
WooCommerce is hard to set-up and you will probably brainfuck yourself in the beginning, but once you set it up, you will have more knowledge about setting up stores than anybody who uses Shopify and then it will be easy to go further, just like Shopify. Setting up Shopify is easy as fuck though, anybody with a brain can do it without any tutorials.
You need to pay 29$ every month for Shopify, you can host and get domain for WooCommerce for 29$ for a full year (and if you're smart, you can get it for a lot cheaper. I have spent 8$ in total for domain + hosting for an year).
You can host more sites on one hosting on WooCom, but in Shopify you'll have to pay more to open another shop.
WooCommerce has security issues, yes, Shopify has more security and on a bigger scale. However, with research, you can protect Woo pretty nicely too.
Internet is filled with tutorials and problem solution for both Wordpress and WooCommerce, so that's great if you run into any problems. Shopify has great support, so you can just contact them to solve your problems. Both are alright in this sense.
There are fuckton of plugins for both, people saying Shopify has more plugins haven't tried WooCommerce to the fullest (I haven't either, but I can tell already that there are lots of them).
Shopify is faster than WooCommerce, though. Loading times are faster, but you can catch up to them with a good host and good plugins. It also depends on your theme.
BIG BIG Advice: Only choose themes that have a Visual Composer or theme editor with them in-built. I've wasted so much time in trying themes only to end up mindfucked because it's harder to edit these themes without theme editors.
Shopify will cost a lot in the long run, everything comes with a Monthly Subscription. Even though it looks attractive in the beginning because of the trials for everything and the fact that we think we'll be able to make sales before the trial ends, trust me that's not how it usually ends. If you can afford to pay around 100$ for your shop every month (atleast) (in the long run, if not in the beginning) and want everything to go smoothly and easily, go for Shopify. If you want more freedom and are low on budget, go for WooCommerce.