THIS IS A TABLE THAT EXPLAINS THE FIRST CONDITIONAL

IF	condition	result
	present simple	WILL + base verb
If	I see Mary	I will tell her.
If	Tara is free tomorrow	he will invite her.
If	they do not pass their exam	their teacher will be sad.
If	it rains tomorrow	will you stay at home?
If	it rains tomorrow	what will you do?

AND THIS ARE THE LINKS TO THE EXERCISES

http://www.englishgrammarsecrets.com/firstconditional/exercise1.html

http://www.englishgrammarsecrets.com/firstconditional/exercise2.html

http://www.englishgrammarsecrets.com/firstconditional/exercise3.html

http://www.englishgrammarsecrets.com/firstconditional/exercise4.html