I have only been reloading for a little over 3 years. I only reload handgun ammo--9mm,38,357 and 45 acp. Hopefully will start doing .223 this winter.
Pistol cases rarely have to be trimmed. I measure some every so often and have never had to trim one.
Rifle needs trimming pistols do not.
Some say just reload the casees till they split. I have 9mm cases that have been reloaded 5+ times and look as good as new. I was just doing a batch of about 300 38 and 3 of the cases had split. Those go in the recycling can and the rest got reloaded.
For bullets I prefer copper jacketed. I've heard that lead can cause some nasty fouling and others say it's fine. I'd just as soon not take any chances plus I reload in my house and I don't really need a bunch of lead dust floating around.
Hope this helps