No, your sentence does not sound good. It is written in very bad English. All you want to say is: By participating in these meetings, we hope to gain up-to-date information about cycling. We also hope to help promote cycling by working with you. Simple English is best. Please note that "riding" means horse-riding.

Original: Our participation at these meetings not only aims at gathering important information connected to the world of riding but also brings a real contribution to the development of this sector , showing people who govern and take decision, studies and proofs of companies which want to cooperate with us and making the world of bicycles boost. This sentence is way too complex to me to understand it. I think the listener would get lost. I recommend breaking it into two shorter sentences for clarity. The first sentence could read: Our participation at these meetings not only aims at gathering important information connected to the world of riding but also brings a real contribution to the development of this sector. The second sentence is confusing to me. What is the subject of "showing" -- participation? What is the direct object -- studies and proofs? In American English, we MAKE a decision, not take a decision. British English may be different. For restrictive relative clauses, "that" sounds better than "which". I've tried to simplify the second sentence but I'm not really sure what you're trying to say. "Boost" needs a direct object. Our participation will show the decision makers studies and proofs of companies that want to cooperate with us and boost the development of the bicycling world.

Our participation at these meetings not only aims at gathering important information connected to the world of bicycle riding (bicycling) but also brings a real contribution to the development of this sector, showing people who govern and make decisions, studies and evidence regarding companies who want to cooperate with us and boost the visibility of the world of bicycling. I took the liberty of changing a few words to smooth out the writing. I hope this is what you were trying to say. Good luck!

"In addition to fill (OR THE FILLING ) in the operations manual, we also provide advice in technical field". ???????