Jettt

As @RobFRaschke said, zen 2's precision boost basically maxes out the performance. You could try overclocking, but don't expect any better results.

Overclock if you want to. Without an aftermarket cooler I wouldn't suggest it on the CPU, but the GPU would probably be fine with a little overclocking. You might be able to get 10-15% extra performance out of your parts, but it is by no means necessary to get a good experience out of them.

No. Ryzen 3000 series doesn't do any better on manual overclocking than on Precision Boost. PBO doesn't seem to be working right, or is just on all the time IMHO, either way, Ryzen 3000 just works and you're better off leaving it alone.

I guess not then. 
Of course, It would greatly improve the performance but it's not like it's going to be used for gaming or anything more demanding. 
I think you're right about finding a laptop w/o one so that you can get better specs in other parts of the laptop such as storage as an example. 
Maybe look for something with more RAM?
It's up to you, If you think the videos you will be editing are quite light then go for no GPU. That's what I would do. Maybe even something portable. (actually, scrap that idea, we don't do those here.  )
This answer's not great, I cooouuuld give you recommendations or something but I'm like. About to fall asleep, so.
Good Luck. 
 

Best for your budget:
Asus Zenbook UX430UN - 8250U, 8GB, 256GB SSD, MX150 (8W), good IPS, mostly aluminum chassis
Acer Swift 3 14 - 8250U, 8GB, 256GB SSD, MX150, IPS, metal chassis
Acer Swift 3 15 - 8250U, 8GB, 1TB HDD+128GB SSD, MX150, IPS, metal chassis
 
Good, if you can ignore those cons:
Lenovo Ideapad 320S 14 - 8250U/8550U, 920MX GDDR5, IPS, mix of aluminum and plastic chassis
Lenovo Yoga 520 - 8250U/8550U, 940MX GDDR5, IPS, mostly aluminum chassis, unfortunately it's has a lower capacity 35Wh battery not the regular 52Wh which leads to mediocre battery life
Lenovo Ideapad 320S 13 - 8250U/8550U, good IPS, mediocre battery life, mix of aluminum and plastic chassis
 
4GB RAM needs to be upgraded to at least 8GB. Upgrade SSD too if you want.
 
I also looked for websites like elnstore.com, villman.com, siliconvalley.com, benstore.com and galleon.ph

Thank you guys! I'll start saving up and see if I'll get a pc upgrade + programs and peripherals or a new pc + monitor

There's these on sale right now and it looks pretty solid based on the reviews. For that budget though I'd suggest going wired because low end wireless headphones might give you some delay and weird hisses.

Hey Jettt,
 
thank you for your help and tip to get a dynamic microphone. I am using the Samson Q1U right now, because the Audio Technica wasn't available in Germany. It does work pretty well, even with a distance of 30 cm from my mouth, it is recording in games, also music etc. just my voice. Awesome. Now I am looking forward to get a better microphone stand and a pop filter.  

A dynamic microphone would be great for that.

I think the Samson Meteor or the Audio Technica ATR2500 would work well for you. You'll also have extra money to purchase a pop filter and maybe a boom arm.

Thanks,the battery life might be a problem but  I'll see if it's available in my area

Thanks, I think I might go for the Audio Technica.