We started feeding my daughter solids at 3.5 months and she didn't want to eat off a spoon at all. More of it was all over her face than in her mouth. So we put in her bottle with formula for about a month. We changed the nipple and the type of bottle a) so the cereal went through the nipple easier and b) so she knew the difference between a "food" bottle and a regular bottle. Then at about 4.5 months I just tried the formula with a spoon and it worked. After a while you won't have to mix it with a lot of formula. And try serving it couple of different ways runny, thick etc. Babies have their preferred consistency you just have to let them tell you. My baby prefers thick --if its runny she won't eat it. The one thing I am learning is that babies have to learn to eat solids (texture, taste and how it gets in their mouths are all an experience).
I don't recommend mixing it with fruit to start. Food is about learning for them you want them to taste the purity of foods before you start mixing. We introduced food in the following order a) cereals (rice, barley, oatmeal) b) vegis, squashes, carrots, sweet potatoes first, then green beans, broccoli etc. c) fruit was last hoping to "seed" a taste for vegis. And we serve fruit on a limted basis and only with breakfast or as dessert.
And if your baby doesn't like spoons then alternate between a spoon and your fingers until they get the hang of it.
I hope this helps. Feel free email me with any questions.