The first conditional describes a real situation with reference to the future. If the condition is fulfilled, the actionA general term expressing that somebody or something does something in the main clauseA clause that could be a sentence in itself. E.g.: I wouldn’t go there if I were you. ("I wouldn't go there") When I arrived he was surfing. ("he was surfing") is likely to happen.

if-clause with present tense (any)
main clause with future simple or continuous

She won't be happy if you tell her the news.
If I break my leg on the ski run, I won’t be giving a party tonight.

The use of present tenses in the if-clause of the first conditional is similar to that in future timeA concept which is related to our perception of reality; that part of existence which is measured in seconds, minutes, hours, days, weeks, etc. clauses. 

• First conditional and GOING TO
• First conditional and imperatives
• First conditional and present continuous
• First conditional and present perfect

Zero conditional with present reference
IF-sentences and conditionals First conditional and GOING TO