Hi Nancy - my recs would be to either use a chimney starter over a metal bucket or bin in a designated area, rattling gently before transferring the coals to the kettle, or playing with your vents. On my Weber Performer, if I'm not using the gas starter or chimney I start with vents half-closed, then open after they've started to take. If I'm using the lid at all, I make sure to narrow both the lid and kettle vents, since two wide open vents + Weber lid usually = ash ghosts flying all over your chops.
Edit on reread: if it's ash coming out the bottom rather than flaking up from the top of the pile, you can get a replacement (or first-time) ash catcher from
Weber, or Amazon has a bunch of gadgets. Metal bucket + cinder block also does the trick. I saw but can't find at the moment a DIY website for converting any kettle using the $7 One-Touch replacement kit.