What is the best prime lens for doing portraits on a Sony Alpha camera? I just bought my first real camera—the Sony a7c—and I am so incredibly excited to start taking photos that don't look like they came from a phone but honestly I have no idea what I am doing and all these numbers are so confusing. I really want that super blurry background look for my sisters wedding which is coming up in about two months and I heard a prime lens is the way to go because it doesn't zoom and that makes it better for some reason?

I've been looking online and I keep seeing people talk about 50mm and 85mm and then there is this f number thing like f/1.8 or f/1.4 and I'm just totally lost on which one I actually need for people pictures. I'm gonna be taking most of these outside in a park here in Seattle so it might be kinda cloudy or rainy and I want her to really pop out from the background trees and stuff. I saw one video saying 85mm is the king of portraits but then another guy said it makes you stand way too far away from the person you are filming or photographing so now I'm just second guessing everything.

My budget is probably around 600 or 700 dollars max because I already spent so much on the camera body itself and my wife is gonna kill me if I spend another thousand on just one piece of glass lol. I saw some brands like Sigma and Tamron are cheaper than the Sony ones but are they actually good or am I gonna regret not getting the Sony brand? Also I read something about crop factor but I think my camera is full frame so does that even matter for me?

• is 85mm too zoomed in if I'm in a smaller area?
• do I need the f1.4 or is f1.8 enough for that really creamy blur?
• should I just get the nifty fifty everyone talks about since it's cheaper?
• is it hard to use a lens that doesn't zoom?

Sorry if these are really dumb questions I'm just a total beginner and every time I watch a youtube video they use words I don't understand like bokeh and chromatic whatever and I just want my sister to have nice wedding photos because she can't afford a professional photographer and I really want to step up and do a good job for her and make her look amazing...