In the UK I would say your two biggest problems indoors are vine weevil and red spider mite.

There’s a soil drench on the market for treating vine weevil. The adults bite notches in the leaves. The grubs eat the roots.I think there’s also now a nematode (worm) control available for them.

Red spider mites like dry conditions, so regular misting with a fine spray can help to control them but I think there’s a biological control available for them too, now.

Dont water your plants from above..Water them from soil level..water on the foilage of most plants can cause many fungal diseases

Plants diseases cause from many different sources. Sometimes from bugs, but mostly from soil condition. You can check your soil condition by pro or get some help from library books. Two quick simple checks you can do yourself: There shouldn’t be no roots showing above the soil, and if the water drains well or not.