A few questions from a beginner (modify a parameter on a GET request and repeat a test step)

Hello all, I'm a beginner when it comes to both SoapUI and testing, so please forgive me if these are really silly questions. I just wanted to clarify that I'm not looking for you to make my 'homework', rather some pointers or guidance.

Here is what I'm trying to achieve:

1) I have a few GET request that looks like this:

Is there a way to dynamically modify the number? If so, where should I be looking?

2) Similar to the previous question, I have some GET requests that looks like this:

Also, is there any way to dynamically modify that value?

3) I made a Test Step using a script I found on this page, so I can load a random value from a file into an HTML tag. However, if I add this Test Step to a Load Test it will be only run once per thread. How can I get to run it several times per thread so I can generate more and different request each run of the Load Test? In other words, I would like to be able to simulate, let's say, 10 request per thread with random values (generated from the file).

Any advice will be greatly appreciated! Many thanks for reading this far.