you can file patent application online using EPO online. however they are require you to provide complete application.
what is the cost of the provisional patent application?
already answered:- Cost of patenting in Europe
If patent application has 15 claims and 35 pages then official cost for natural person will be approximately 600 EUR. see Article 78, Rule 17 and Article 14(4). Time limit for providing fee is one month.
How long it will protect my product?
If granted patent will protect your product for 20 years from date of filing.
Where to look?
Guide for applicants, Part 1: How to get a European patent
Requirement of Attorney?
If you have your residence or principal place of business in a contracting state, you may act on your own behalf in proceedings before the EPO
If you have neither a residence nor your principal place of business in a contracting state, you must appoint a representative and act through him in all proceedings before the EPO other than in filing your European patent application and paying the fees.