There are several hundred thousand words in the English language. However, few people would claim to know them all, and you need to learn far fewer words than that to be able to start using the language. Most people who want to learn English probably know several English words already. This is partly because songs in English are broadcast on the radio throughout the world. Further, English is the language of the Internet, which most people use or aspire to use.
Every language has its own rules for the way words are used in phrases and sentences. This is what we mean by grammar. For example, it is not grammatically correct to say: "I shops to the went," even though most people would understand what is meant. Grammar defines the correct word order and also how tenses work. For example, if someone says "we rode our bicycles," we know they are speaking about more than one person and that the event took place in the past.
When you speak or write English, you should use punctuation to help the reader or listener understand. Punctuation includes commas, periods, apostrophes, question marks, colons, semicolons, parentheses and brackets. There is probably more disagreement about how to use punctuation correctly than about how to use grammar correctly. Furthermore, many people regularly use English without any punctuation when they communicate through texting, which shows how flexible the English language is.
To make progress in English language study, try to take a night school course. This should give you a good foundation for further study. Alternatively, or as well, study online, where you will find many free sites to help you. Listen to songs in English and try to work out what the singers are singing about. Get English-speaking pen pals or email buddies to write to and ask them to correct your writing for you. Don't be surprised if you get different ideas about what is correct usage. Every person who uses English uses it slightly differently from everyone else.