Sex toys

So I’m 22 and never had sex or used a sex toy. But I’m interested in buying a dildo. I’ve been looking online and there’s one that is 5 inches long and about 3.7 inches at its thickest. Do you think it’s necessary to buy lube as well? It is a pretty thin dildo so not 100% sure I’ll need lube. But what are your opinions?

Also does anyone think this is too small/too big? Just remembering I’ve never really had anything inside me before...