How to pick a developer

So today I posted a small task on the WordPress jobs site. I’m pretty overwhelmed by all the responses I’ve been getting..! It’s pretty great.

Now.. I am quite a rookie to all of this. Are there any pointers to making a decision who to give the task? It concerns a minor customization to my woocommerce shop that needs a little bit of coding. I assume a developer is going to need my ftp and my wordpress admin credentials? Not that there’s much on there right now, but still, I’m completely new to this so any thoughts on who to trust? Thanks!