You can find the dedicated tutorials for Construct 3 on our website. You can check out also its online manual out and the How do I FAQ topic which lists examples of implementation and answers to the usage of Construct 3 from our forums.
Be sure to check the general Learn section of our website.
We strongly recommend starting with our beginner's guide to Construct 3.
You can also, when executing Construct 3, find bundled examples in the editor, from the start page.In the left column you can select from full game demos up to advanced demos and tech examples.
You can also make use of the templates provided to kickstart your new projects.
You can find a dedicated tutorial How to learn Construct 3? Next steps for beginners that relies on the examples and templates from the start page to help you using Construct and its elements as soon as possible.
There is also the How do I FAQ for Construct 2 (those examples can be used with Construct 3 as well, so checking out this massive thread is still relevant).
It is possible, hearing from the description of your issue, that you might have made use of new object types instead of instances.
There is a major difference between those two elements in Construct and it can cause issues to beginners.
Also, for applying actions to a set of different object types, you might gather them in a family.
When you encounter an issue with Construct, check all the previously mentioned existing documentation, and if you cannot find an answer then, post in the How do I forum.
Be sure to provide a local copy (.c3p) of your project so other forum members can check it out. Make sure it focuses on your issue and is not using third-part addons.
Provide exact reproduction steps, what you expect your code to be doing, what you experience it happening and it will be easier for forum members to provide you with an accurate answer to your issue.