Below are websites where you can choose to practice and expand on your knowledge of conditionals
The English Page-Conditional Tutorial
This site provides you with explantations of the English conditionals in additional to several comprehensive excerises. The excerises range from practicing one type of conditionals to excersices where conditionals are mixed and you have to choose the correct form. Great for pre-intermediate and intermediate students
Perfect English Grammar- Conditionals
This is probably one of my favourite sites on the web. For the conditionals, this site is good if you need to revise the structure/ form of conditional sentences but may not be so good at providing lots of examples. That said, there are great excerises on here for all the conditionals. Just be aware that there are two sets of excerises which are in PDF of form. This is would be great for teachers to use as an in class activities (I have used it as a pair excerises) or for students who seek that extra bit of practice and challenge. Suitable for pre-intermediate and intermediate students.
British Council- Conditionals
This is a very good site which provides good explanations and examples of the conditional. There aren’t many excerises on here but the ones that they do have are very good. You have to match the sentences halves together which tests your knowldge of the structure of conditionals. Very good for revision and extra practice. Suitable for pre-intermediate level students.
English Grammar 4U Online- 1/2/3 Conditionals
This link only directs you to the practice excerises. The site only focuses on the first, second and third conditional. The format is gap fill and word selection. Excerises are brief and suitable for pre-intermediate level students.