You are better off reading and seeing some of the video tutorials on TestComplete here https://support.smartbear.com/testcomplete/docs/index.html. It's very simple to learn providing you know the basics first, and majority of the content is clear and simple to follow.
Ensure you read the information about Python and the limitations here https://support.smartbear.com/testcomplete/docs/reference/language/python/index.html. There's plenty of materials on the internet, on programming in Python.
The errors/issues you have described are very common, and are mainly relating to not knowing how TestComplete actually works.
Depending on whether you want to test a web or desktop application, you have to choose the appropriate way of identifying UI objects, as describe here https://support.smartbear.com/testcomplete/docs/testing-with/object-identification/index.html
Not forgetting, the community forum can help too.