Feel free to add me on steam if you want to play your map with us one day. I already have it posted on my server and we can give you real-time feedback if we come across any issues or comments while playing.
A: MvM usually isn't good for a first map, especially here because it's hard to get it tested
Not unless you know where to search and ask for help on testing. The mvm_underground map maker came to 2 of us for testing his map out and he's almost done with his final map version.
On the note of your first map being an mvm map, I salute you for that. I for one could not even manage to properly make a single square room in hammer, and mvm maps are one of the hardest, if not THE hardest, TF2 maps to make. Be proud of yourself.