Sometimes I think seeds go past their ‘use by date’. I’ve a few sunflowers etc. that the kids lost in their room for years and when they reappeared one day they never sprouted! I’ve also had more luck raising indoors, on the window ledge, where I can keep an eye on and water as needed; although have had transplanting problems with this method. Some seeds I find easier (eg mustard, pea,) than others (eg native flowers).

Check with a Garden Centre as some plants like fertilizer to start them off, others don’t like any. Some need specific types of fertilizer / soil conditions.

It might depend on the seeds. Where do you get them from- a plant nursery, direct from other gardeners, or online? Sometimes online sellers are dodgy, and sell seeds that aren’t what they claim to be (even for plants that don’t actually exist, like blue strawberries), or are old and won’t germinate. Also, check that the seeds you are trying to grow are right for the climate where you live and that you are planting at the right time of year.

I think it comes down to good soil, the right position, amount of water, amount of sun and distance between the seeds. I prefer to buy seedlings above seeds.

Are you watering them enough? Are you planting in the right season? Are you ensuring they have the right exposure to sun, some flowers love lots, others not so much

I have had similar problems, but now its ok. I just make sure I water regularly and protect from too much sun in the summer time. also check the age of the seeds as they do have expiry dates on them. good luck I hope you manage to grow something as it is very rewarding to eat your own vegetables from seed.

Check that you are sowing your seeds at the right time/month/season. Always follow the instructions on seed packets for sowing depth. try watering with a mist rather than a stream of water. Don’t give up

It could be the soil, try some soil improver and I second the comment about growing into a seedling in the sun before transplanting

Maybe try small pots first or. Get a fertiliser?

When I grow from seeds, I put the seeds in small pots, leave them inside the house, close to a window that get regular sun and give water regularly. It takes time but eventually they grow.