In English the ¨rules¨ for spelling and pronuncation have so many exceptions that they are hardly rules.  Here is an overview: https://www.understood.org/en/learning-attention-issues/child-learning-disabilities/reading-issues/14-phonics-rules-for-reading-and-spelling?view=slideview

To help you know how to pronounce a word, you can use this site:   https://tophonetics.com/es/  Enter the word in English, choose American or British, and it will give you the IPA phonetics and you can play an audio file to hear how a word is pronounced.

Here is a site that is good for learning pronunciation and learning IPA phonics:

http://soundsofspeech.uiowa.edu/index.html#english

Here is a vowel chart.  The chart represents the position of the tongue in the mouth for the different English vowels.

http://www.ugr.es/~ftsaez/fonetica/vowels.pdf

I agree completely that you need to practice with a native speaker who corrects you.  Practice reading with that person, so that you mentally connect the spelling with the pronunciation.

I would also use this excellent site:  (sometimes it is inaccessible, just try again a little later, it is well worth it)

http://easyworldofenglish.com/pronunciation/pronunciation.aspx?c=2c21d1bcc5bb2345

Choose the category Minimal pairs  (Also  these are very useful:  T&D sounds, Special endings).  

This website has series of words with similar sounds in two different columns, so you can get used to distinguishing the proper sound.  First listen to them and repeat; then try to say them before playing the sound and then correct yourself. Once you have finished, click on next to see the next set of words.  Once you are done, click on the next tab at the top to practice different types of sounds. 

Then go back to the website the next day or a few hours later and try again to make your learning more solid.  First try to pronounce, then listen and correct yourself.  If you are making a lot of mistakes, just listen first and repeat. You will mentally connect the spelling with the sound, without realizing it.  It is a very good exercise.

I believe that it is better to develop a 'feel' for the sounds by practicing while reading, rather than trying to learn too many rules, because English is terribly rebellious when it comes to sticking to any set of pronunciation rules.

I hope this helps.

I'm not on board with the whole "practice with a native speaker to learn pronunciation" theory. I use native speakers to learn conversation, not pronunciation. Very few natives are good at teaching pronunciation, ime, and it's very stressful trying to learn it in front of someone.

So what do I do? I learn the alphabet and pronunciation of phonemes first, using a resource that is designed just for that. It must have audio, of course. Then I learn it at the word level, and finally sentences, by doing a lot of repeating words/sentences after I hear them. The resource I use for the sentence level is Pimsleur. 

I've found my method works much better for me than being doggedly corrected by native speakers. By the time I get to conversation practice, there is very little if anything to correct, and my conversation partners rarely feel a need to criticize my pronunciation.