Folks are talking about two different sports - fishing and catching.
I know they are different. I'm OK at fishing, but not so good at catching. ;)
For basic fishing, nothing beats: hook, line and sinker. Just need a big glob of worm on the hook and you're good to go.
Also - get some swivels (don't cheap out on this) and a variety pack of bobbers. For father and young son fishing, nothing beats watching the bobber start bobbing around, then take off.
A cheap way to keep things from tangling is a swivel. Get good quality ones. The cheap ones won't turn under tension or will open up under load.
There are different types and qualities of line including multi and mono filament lines. I bought an expensive multi-stranded line from Bass Pro, but after years on the spool, it hasn't turned into a slinky. I was given a cheap spool of mono-filament that would break if I tugged on the line. Find out how to tie on the hook/lure. Different types of lines require different types of knots.
Check the rules and regulations for your area. Do you need a fishing license? Which species are in season?