re: "Need tips on how to trust freelancer"
There are some freelancers you should trust.
And there are other freelancers who should not trust.
And there are other reelancers who you don't need to trust.
Ghadir, below I have typed out goals for you:
My name is Ghadir.
The most important part of my website is the domain name. I control that. I don't let ANY freelancer have the access credentials to my domain name registry account.
So if things go wrong with a high level freelancer, I can always maintain control of the website.
My website is backed up regularly to an archive location that I control.
The data are backed up.
The source code is all backed up.
So if things go wrong with a high level freelancer, I can always restore the website using the backup archives that I have access to and control.
I have practiced using these techniques. I know that if something goes wrong - either for technical reason, or due to human malfeasance - I can restore my website to full functioning order.
I know that most of the people who work on my website only have limited access. The blog writers - for example - can edit the blog articles they created and they can create new blog articles. But they don't have the access needed to alter the design. The designers are able to do their job, but they can't change the site's main source code. Neither the designers nor the blog writers have access to the user accounts. All of the people working for me have the access privileges that they need to do their job, but not more so. All changes are tracked automatically. If one of my administrative assistants makes a change to an order, I know WHO made the change and WHEN they made the change.
Have a voicce-to-voice chat and explore a fit. Any freelancer willing to do anything you want for peanuts cannot be trusted to complete the work. Any freelancer who feels shady probably is. Any freelancer who lets you bully him is a bomb that will eventually explode.
On hourly jobs limit the weekly hours until he's proven himself. On fixed price jobs establish several miilestones so that the freelancer can't take the money and run. Any freelancer suggesting you go outside Upwork for payment is trying to cheat UW. Why would you ever want to do business with a known cheat?
Preston's answer is how to defend yourself against freelancer malfeasance, which is critical. My answer is about the red flags that should have you hanging up on the person.