My personal Telegram messenger - for all questions. I never answer calls from unknown numbers. Please write a message. I also never answer text messages from strangers like "Hello" and any voice messages - please write details in the first message right away.
My personal email address - for all questions. I try to read all incoming messages. If I don't answer for a long time - please send the message again (maybe I missed it or it went to spam) or write to the messenger (Telegram). If I still don't answer - it means I'm not interested, thank you.
Social media - in theory, I can answer in a personal message on my social networks, but not a fact (I can miss the message) - so it's better to write to messenger or via e-mail.