Your English is perfectly fine, no problem there
As for your question, you could consider using a database, especially if there will be a lot of information to be presented for each result. For example, in a MySQL database (free), you would have 1 column dedicated to the name of the fish and this column would be unique (i.e. your primary key). The other columns would be for plants, food and whatever else. Since each row would be dedicated to a particular fish, you would retrieve that particular row based on the user's selection.
If there will be multiple questions, then you need to figure out how to calculate the final result. It can be done through a series of if-else statements but that logic is something you need to work out, unless you provide an example of the logic and the choices.
The HTML portion is rather simple and can be written from scratch, same with the PHP and database portion. You could check out CodeIgniter as a PHP library resource to help you out. There are tons of examples, temples and libraries out there for the HTML and CSS portion, choosing the one you want somewhat comes down to how you want it to display.