Asking Date of Summit

This is not a complete independent clause. However, the rest of your post feels like an email so if that is the case, email subject lines are commonly written in this style.

Our chairman, is considers toing attending the regional meeting but we would like to learn what kind of costs are included in the 700 CHF per person.

IDoes it inclusive ofde accomaodations?

Second matter, we want to join the annual summit held in Mexico but we need to know exactly when the summit is going to be held as we have to make application toapply for visas.

Because finding a visa appointment might be difficult for us as the date of summit is getting closapproaches, please share this information at your earliest convenience.

Another user said "because" cannot be used at the beginning of a sentence. This is not strictly true, however it is commonly used incorrectly. To start a sentence with because it must be a part of a dependent clause providing a reasoning for a following independent clause. I have provided a correct use case for this above.

Asking Date offor the Summit Date

Our chairman, is considers toing attending the regional meeting but. First, we would like to learnknow what kind of costis included in 700 CHF per person fee.

IDoes it inclusive ofde accomamodation?

Second matter, we want to join the annual summit held in Mexico but we need to know exactly when the summit is going to be held as we will have to makesubmit visa application to visas.

BThis is because finding a visa appointment might be difficult for us as thedate of summit is getting closwe approach the summit date.

We don’t start written sentences with “because”