Replying to Editing Issues Help Wanted

Hello NS

I'm currently having some issues with the way I edit. I have all the film on my iPhone 5s and I made a 86 second video. The shitty part is that when I go send the video via email to my computer It says the video is too long and I have to trim it down. so i trimmed it down to 54 seconds and then took what was left (32 seconds of video) and sent them sepparetly to my computer. i was able to download the two videos onto my Mac and now i don't know how to put them together into one video. I've tried very hard to edit on my computer but its just too confusing to me. I do have iMovie on my computer but I don't know how to use it. Can anyone out there help me out??