Wearing the uniform is part of the ethos for young members and leaders. So, as a leader, you would be expected to wear a uniform for all formal events and meetings. Activities are usually carried out in clothes most suitable for the activity especially where safety is concerned. Helpers do not have to wear uniform although it is encouraged as it helps promote the togetherness of Scouting. Of course previous experience of Scouting or working with young people will help you but it is not necessary.
Training is provided for all leaders.
Specialist skills are useful but not necessary. Everyone brings their own skills to Scouting which may not be as dramatic or specialist in nature as Mountain Climbing or Canoeing but nevertheless contributes to the weekly meeting. Camping is an important part of of Scouting but not to everyone's taste. It is important that young people in Scouting have the opportunity to experience camping as part of the whole Scouting experience but usually there are sufficient people around to ensure these experiences can be provided. Camping does not automatically mean staying overnight in tents in remote fields and making your own 'facilities'.