Link to website down after updating plugin

Hello,
I’m new to wordpress and literally know nothing about website development ?? This morning I tried to update a plugin on my website and afterwards it started to get ‘buggy’ in that some widgets were just being left off the website all of a sudden and also some plugins were activating themselves after I had just deactivated them. And then the website crashed and now I am unable to view the website at all. I can access it through the back end but as soon as I just go straight to the website the page goes blank. Any suggestions?
If I type in the website without www. at the start it seems to load but as soon as I type in www. at the beginning it goes blank. The website is https://www.inspiredexplorers.com.au if you want to have a look for yourself.
Also, there’s an update for wordpress that I want to get and I need to back up my data. I had a read through the instructions but it doesn’t make much sense. Is there an easier way to backup data just through the back end of the website?
Thanks for your help!