As others have said the real key is low carb. Especially avoid high GI carbs like bread, baked goods, cereal, white rice, mashed potato. Very sweet fruit like pineapple is also a problem.
Some people find small amounts of low GI carbs are ok (like new potatoes, pulses, oatcakes). But it varies from person to person what causes a spike and what doesn’t. You might need to experiment a bit.
Tbh I found that cutting out carbs pretty much altogether (except the carbs in veg) was easier. So most meals for me were just protein plus veg. Snacks were nuts, avocado, cheese, hard boiled egg, salami. I found snacks between meals helped avoid spikes.
Glucose Goddess on instagram has loads of tips for avoiding blood sugar spikes - she wasn’t around when I had GD, but I imagine her tips would help here too. A few of her tips to help avoid spikes that I can remember: eat the veg/salad at the start of a meal rather than the end. If you do eat carbs, have them with some fat or protein, not on their own. Add vinegar or lemon juice (eg in salad dressing or pickled food) to a meal. Go for a short walk or do some other exercise after a meal.
Having said all this, some women just can’t control their levels with diet alone and need medication - and that’s ok! (Though does affect birth choices eg more likely to be induced).
The most important thing is monitoring your sugars and keeping them fairly well controlled. All the dangers you’ve read of are from uncontrolled GD.