Are there cheap 150 200 euro max laptops that you can equip like e.g. A new cpu or if it also works gpu one with 16gb ram would be nice.
With laptops you can only upgrade the RAM and the hard drive (or SSD)
No. Laptops in general can only be upgraded to a very limited extent, if at all. Expanding the RAM and hard disk is usually the only thing that works.
And even these components are often firmly soldered in very cheap notebooks and can't be exchanged or even upgraded.
If you want to be able to carry out hardware upgrades, there's no way around a tower PC. Laptops are "bought as is, please buy a better model for more performance".
For 150-200 euro you can hardly get a laptop, the (extremely rare) ones where you can upgrade the CPU then cost more than ten times as much.