problems with adjusting the pages

Hello everybody,

My English is not so good but I will give it a try !
I have build a website for the company I work for.
I found on the internet that wordpress would be ideal for this.
It was easy to do…
In the beginning it wasn’t hard but now I have sevaral problems.
I would like to make some changes to my pages.
I would like to add some new pictures en change some texting.
This does not work..
When I go to “change page” it will not open, the circel will keep going around :-(…
I am not very talented with the internet.
So please try to subscribe it in an easy way how I can solve this problem.
The things I’ve tried to do are:
– Close all the plugins en open them one for one.
– Tried to remove the theme ( don’t now how to do this ?)
– Refresh wordpress

All of these things didn’t work ?
There is also a layer slider that doesn’t appear on the website. I’m sure it’s there…but you can’t see it.
When I search on the internet to take a look at my website there are more issues that pop up.
Is there anyone who could help me please ?

Best regards Linda