Launching a beta is always difficult, sometimes they take off, other times people will show an interest and not necessarily engage until much later on. Just try and be ready to be flexible and not tie yourself up with meetings or anything that can take you away from focusing on what users might be doing in the platform and/or any issues you might be getting along the way. If users are engaging with you whilst signing up and using, give them as much attention as you can, there is a real opportunity to build your relationship with them here and ensure they continue to use your product beyond beta. If you get negative feedback, try not to take it personally. If it relates to an immediate issue, of course prioritise and ensure they are kept in the loop, if it is because the tool lacks anything or they just don't like something, just log it. Ideally if you have a ticketing system, great to put every little bit of feedback in there.