The parts are all old. The main performance boost will come from upgrading the gpu and CPU.
The 3070 will be a massive bump in potential performance, but depending on the games played, will be bottlenecked by the cpu and ram.
Upgrading just the cpu or just the ram doesn’t make much sense, they are sort of tied together, along with the motherboard.
So, what I would suggest is that you pick up a new cpu, ram and mobo bundle.
The 3070 upgrade can happen before or after that.
A new mobo will also come with a m.2 ssd port, which would be a massive bump to boot and load speed, but negligible for game fps. But that can be done later also.
You can look to PcPartPicker.com to see what others have put together.
You’re looking at what cpu, motherboard and ram they use.
Here’s a nice example that won’t break the bank: https://pcpartpicker.com/b/6Vhtt6
And here’s one from the other end of the scale 😁: https://pcpartpicker.com/b/WkVcCJ
He’s your King, boy!