I use Shotcut. It functions a lot like the higher end editors but without the hefty price tag. I haven't found something that I wanted to do with my videos that I couldn't with shotcut aside from after effects but that's a whole other issue.
I use Adobe PremierePro CC and After Effects CC. For Thumbnails and others, I use Photshop and Illustrator. I dont recommend a cheap, free editing program. If you enjoy doing videos, invest some money. It'll be worth, believe me. But if you really do not want to pay, try the software "Hitfilms". It's similar to PremierePro CC but's free. It's not bad and you pay only if you want to have additional features. Hope I could help you.
I use CyberLink PowerDirector 16, AVS Video Editor, Corel PaintShop Pro X9 I think that's enough for me...ive tried Sony Vegas but I didn't like it so tried the above and stayed with them for years now.