
This isn't a very exciting choice, but black tea with milk and a little bit of sugar is great imo. The milk softens the taste of both the sugar and the tea and I love it. And because you're putting in your own sugar, you're in control of the level of sweetness!
Another kind of tea I loved is, well, technically a herbal infusion I guess, but hibiscus tea! It's a bit sweet and a bit sour even without adding any sweeteners.

I love earl grey ! It’s a lavender -citrus tea ! Sometimes I drink it with milk to make it creamy , but you don’t have too ! You can also put sugar in it if you’d like . Earl grey will produce a stronger flavor of you don’t put milk in it , but if you do the flavor will lessen to a hint of lavender and cream . Either way I love it ! Keep in mind when making tea every tea is different ! There’s different brewing temps and different steep times ٩(๑❛ᴗ❛๑)۶

I would like to recommand. But I rather like strong tea. Like the one who smell strong and have very spicy tastes. I don't think you would like theses one.
But like the other one said, you should try black tea with milk and honey. (If I have to sweeten a tea and I don't like to do it usually I rather add honey than sugar, sugar tend to spoil the savor of tea imo.)
You can try red fruit flavored tea too. It's to sugary for my tastes but a lot of my friend who don't like tea like theses one.

If you like a slightly sweet tea you could try French vanilla with milk and no sugar. That's very good. I like lapsang souchong with milk and sugar. The tea leaves are smoked and the milk gives it a smooth flavor. Though I don't think you would like as much sugar as I put in but you could put in a bit at a time until you found the right sweetness for you.

If you live in the USA, there are two store varieties I always recommend, mainly because of access and ease of use.
Tazo-Wild Sweet Orange (sharp)
Yogi- Sweet Tangerine (mellow)
It is a tad expensive but Darjeeling, second flush, is a good black and the common one in stores (first flush is lighter and my friend likes it.) If the tea has anise, licorice root, marshmallow (the herb,) vanilla essence, or cacao nibs, they are meant to be sweet. Chocolate teas commonly use vanilla because it stimulates the same tastebuds that chocolate does and it doesn't add artificial flavoring. Licorice root is the most common method.
Since you made it clear you didn't like tea before, black is safe but super cheap can leave a bad aftertaste (looking at you, Lipton.) Greens are easy to burn. I would say four or five minutes in the microwave for a mug of water for blacks and three and a half or less for greens. Cover it for the appropriate time on the box of tea. Taste first before adding sweetener.
Good luck in your tea search. I hope you find contentment.
I hate tea but here I am reading this and so intrigued how the tea taste Like milk is it delicious i want to try it #-.-)