Hello there,
I am new here but have tied for a while. I think that the easiest types of topwater flies to tie are ones that utilize foam in the pattern. I use normall 2mm thick craft foam that you can purchase just about any where for really cheap. There is hundreds of patterns that use it.
Also you can try tying poppers. You can either buy the bodies pre-shaped or you can shape you own out of anything that will float. I have recently been working on shaping my own out of botlle corks.