OK Here goes - from a technophobe. Apologies to those who know a lot more about it than me (in other words nearly everyone).
First you have to get yourself what is called a photo hosting site. This is a website that, free of charge, will accept your pictures, store them for you, and give you a url (link) to each photo. You can then use the url link to move your pictures around on the web, such as sending them by email, or in this case putting them onto another website.
I recommend Imgur (https://imgur.com/P). Register with them and then you can click the appropriate buttons to upload any pictures you want from your laptop.
You will then be able to see a way of copying the url for each picture you want to post on here (it is called "Direct Link")
You can also choose the size of the image you want in the process. Once you have the url of a photo, go to your post on this forum.
At the position where you want your picture to appear in your post, click on this icon at the head of your post:
This then appears:
Paste your url into it and click OK.
Job done.