Lead blood tests
Testing walls, though painting over with many layers may be ok
What’s worth doing if you want to ensure you and your kids aren’t at risk?
If you live in an older house (let's say built before 1980) check for cracking/peeling paint on woodwork. Paint on walls is less likely to be peeling in my experience, but of course be on the lookout for that also.
By now, any lead paint has probably been painted over, so if everything looks solid it's best to leave it alone.
You can buy inexpensive lead paint test kits at any hardware/home improvement store.
Also be aware of older venetian blinds, some of these can contain lead.
https://tompkinscountyny.gov/health/lead/index
Here is what the CDC says
https://www.cdc.gov/nceh/lead/prevention/blood-lead-levels.h...
It is an easy test, ask your primary care provider.