how to connect apple laptop to pc screen

Hi bhh_123,
I understand that you would like to connect your Mac notebook to an external display. I can help you out with that but will need more information as to what you are using. The main thing is to know what kind of Mac notebook you have as you will probably need an adapter to plug it in. Take a look at the next articles to tell you about the specific model you are using.
How to identify MacBook models
https://support.apple.com/en-us/HT201608​
How to identify MacBook Pro models
https://support.apple.com/en-us/HT201300​
How to identify your MacBook Air
https://support.apple.com/en-us/HT201862​
Once we know that, we also need to know what kind of display you are using to know what kind of adapter to suggest. There are a list of adapters in the next article that will help you choose which one to get so you can get the display to work with your Mac.
About Apple video adapters and cables
https://support.apple.com/en-us/HT201853​
If you do manage to figure this out on your own and need more assistance with how to use your Mac with an external monitor, the next articles will help you out and explain the different features depending on what version of OS X you are using. ​
OS X: How to use multiple displays with your Mac in Mountain Lion and earlier
https://support.apple.com/en-us/HT202351
OS X: Using multiple displays in Mavericks
https://support.apple.com/en-us/HT202780
Let me know what you find out.
Have a good day

It's easy to set this up. I use the Apple USB-C Digital AV Multipart Adapter to connect to a Viewsonic monitor using an HDMI cable. Then using the Apple Magic Keyboard and Magic Mouse while the MacBook runs with the display closed. It's easier in this set up to work with applications that require more screen space (i.e. modelling, animation, compositing, video editing).