I’d agree that the meter is pretty close to essential. However, if funding it (or rather the strips, which are the main cost) are a big barrier, then taking a simple approach to eating - cutting out all the big carbs (rice, bread, pasta, potatoes, sugar, root vegetables) would mean that you’d be driving your sugar levels as low as possible and likely not having big spikes.
Having said that, that might not suit you, in which case you do need to understand which foods impact your blood sugars and testing would be essential at least initially.
Aside from that testing helps to alert you to any problems at an early stage, which gives you a better chance of addressing them.
