I learned the lacing pattern from an old wheel and tensioned the spokes until they just recessed into the top of the nipple. Then give a few extra turns and true. You can tell by feel if they’re tight enough; it’s fairly obvious if they’re not. If you spin the wheel and hold the top of a nail against the spokes, the spokes on each side should be at more or less the same pitch.
Between my dad and I, we’ve built four or five pairs of wheels like this using a home made truing stand and mine have held up to a pretty decent amount of abuse. Like lots of things, the most difficult bit is getting started.