My husband is going through this too, diagnosed with a large mass under his kidney with spread to the lungs and lymph nodes. We took a day for ourselves before contacting anybody although we had to let his work know almost before anyone else as they knew he was going for a consultation to review CT scan results. 

Choosing when to tell his parents and siblings was first was because they new tests results were imminent. We tried to be as factual as possible and not tiptoe around it. We were clear on the limbo we were in and that we were shocked. We explained the next step planned and that we would let them know if there were any more news. We gave them a chance to ask any immediate questions and repeated that we would ask those questions and any others that they messaged when we next saw the consultant. All of this needed to be done using video calls as we don't live near them. 

That all happened first because our real dilemma was how to tell our kids, both in their early 20's. One about to go travelling for a month and the other one working the other side of the world. We wanted to be able to give them some reassurance about any urgency and we didn't have those answers so we waited until our first Urologist visit and spoke to him about our dilemma. He helped us understand the next steps in creating a plan of action and we were able to tell the kids that Dad wasn't in any immediate danger, that we had confidence that time would be  invested by an expert team in creating a plan before anything would happen and that we would keep them up to date with any changes and be honest with them. We spoke to the traveller face to face 4 days before departure and as the trip was ultimately to visit their sibling the decision was to go ahead with the trip. The one overseas was harder. We needed to check that a support system was in place and deal with poor wifi connection but we planned for a long catch up call so that we had plenty of time if needed. We followed up with a written summary and some offers of support from other family and friends and planned who they would tell immediately around them so that they could talk it out with others if needed. 

Other family and friends were done ad hoc across a few days. Generally we messaged those who would be positive and supportive first. We created our support team and then we called a couple of family members that we knew would be down and drain our energy. We asked some people to contact others on our behalf to spread the load. We also agreed that we would be really honest with each other about how we were feeling at any time so that we didn't try and 'stiff upper lip' our way through the rubbish days. Although some appointments are at weekends and evenings we have put a boundary on those times that we try and keep them 'cancer free' and don't use that time to reply to messages or do administration stuff. 

The limbo stage is awful but we are getting better at it. Find someone to go through this with if you can. Someone you can talk to or not talk to if it suits you.  Good luck, we're here for you too.