That's good advice youre getting. Travel is a big part of reenacting unless they is a huge glut of groups / events real close to you in your home area. I suggest if there is a multi period military timeline type event, that may have time periods represented from perhaps the 2nd century to modern times, and this is an easy day trip then you get to see what others do - and don't do - and speak with those already doing the reenacting / living history hobby.
Nothing is stopping you from developing your own unit, I / we certainly encourage you to develope a researched impression. If you want great results - research, research, research .... a lot of research is free online - and learn to observe safety with firearms. Even blank loaded WW2 weapons can cripple you.
Wishing you all the very best in your endeavors,
Cheers, Johnnie, 93rd Highlanders 1812-1858.