As an English speaker, it is not easy to learn Chinese. Instead of a phonetic language, mandarin Chinese is a tonal one. More vowel sounds make the language become more musical. To improve your pronunciation, you have to learn some language's rules.
At the beginning, you need to familiarize yourself with easy sounds of the language. In fact, many of them are not too different from English and so you can say them correctly.
When it comes to the difficult sounds, you need to practice as often as you can. Equivalent sound is hard to learn for English speakers. Pinyin helps the non-mandarin Chinese speakers learn to pronounce Chinese characters and improve their pronunciation.
When you learn Chinese pinyin, you should be aware that there are four tones in Chinese language. To perfect the tones, you can get tutoring from someone who speaks the language well or someone directly from China.