Hi, yes business link can be a hit and miss from other peoples experiences, I think you just has to use them for what you need. I too found they were good at talking the talk but when it got to the nitty gritty they were just that all talk. Find out if they have any free courses on the go.
You might not need a licence for certain events, some like indoor carboots may come under "markets" which is over £400 pound a year here. For insurance purposes you will have to have completed a risk assesment and have a record of this.
As to worrying about if people will come thats down to you. What kind of events are popular and what has been a flop. Look at other event and see how you would improve on patron numbers. How do other events do at this venue, is there parking, is it easy to find, will people travel from other areas. Do loads of research, but be careful with how you ask things. Asking expectant and new mums if they like the idea of a baby show is one thing but asking if they will jump on the number 57 bus and travel for 15 mins, then pay £1.50 to get in, is another thing.
Sometimes its all down to advertising. This needn't be expensive it might be flyers in local hairdressers or small posters in the newsagents. Word of mouth gets going once you have had your first event, but before your first one tell everyone you meet carry flyers and don't be shy from the window cleaner to the mums at the gate they are all potential paying punters. Look out for free advertising, such as editorials in the local paper.
If you are lucky and your event is going well it is up to you as the orgainisers to look after the whole event, which may include delegating certain duties.
Think about the point of entry how will you collect money, do you need tickets, who will look after this if you need to attend to something else.
What is the venues limits on numbers, if you are reaching capacity simple get someone to stand at the door and start a 1 out 1 in system, If you are over capacity just don't let any more in until enough people leave.
Make friends with the caretaker/ duty manager. You will have to ensure the exits remain un blocked and fire doors aren't propped open. Ailse are kept clear and other matters of public safety are considered.
At larger events or where parking is involved you may even need to hire stewards. They can do all sorts of duties form directing cars, taking door money and welcoming guests as well as safety duties like manning exits.
I know this is perhaps a bit in the future but its all things to consider.