Yaya I thought it would be easier with solids too! I started Ella at 18 weeks and went great, still is going pretty good but somedays better than others. The main advice I can say is don't push him, just simply offer and if he refuses, try again in a few minutes, if he refuses again, I try once more in a few minutes and if refuses take it away and try at next meal.(Easier said than done as I know it stresses me out more than her:) The eating off the spoon gets better with time, typically at this stage they are practicing with solids more than anything, not really getting the bulk of nutrition with it. I know many people have reassured me off here too that it can take up to 25 times of a baby tasting a food to really develop a like or dislike. Mosly, milk is their main source of nutrition for the first year so don't worry if he doesn't get a ton inside his mouth.
Ella makes faces ALL the time to new foods, that I can't help but laughing at some. It is pretty normal as they are "analyzing" the new food in their mouths. Poops are pretty interesting too, Ella used to be like clockwork, now she may go 3x day or go one day without one, I think this is normal.
I am still going through a lot of this myself so I can just offer a little of what I have learned so far