The first tip is: don’t spend all your energy on this topic. If you’re learning Portuguese, you will shortly understand that there is other grammar content that is much more important for your learning process in Portuguese.
On the first day of your Portuguese course in Lisbon, you will notice that many students will try to learn and understand all the sounds that a native Portuguese speaker can produce. It is not a wise strategy to learn Portuguese. Go with the flow because we are pretty sure that your Portuguese teacher will teach many different sounds and rules over time.

LEARNING PORTUGUESE STEP BY STEP
Don’t try to learn all the sounds on the first day of your Portuguese course! Even if you try, believe us, you will not succeed. So, make sure that you keep yourself focused on the key points of the language. Those key points will give you the opportunity to start communicating shortly.
The only effective strategy to become an expert on Portuguese sounds is… daily communication in Portuguese! You will have to use your Portuguese every day for an extended period of time (2, 3, 4 years, or more). Then, your accent will get better and better and you will finally produce the Portuguese sounds correctly.