As NoSky already mentioned, if you're on strict budget then I'd swap Maths for Abacus which is significantly cheaper.
I'd also swap Koma VCA for Behringer Four Play (clone of Intellijel Quad VCA) and add some LFOs to provide modulation, attenuverter and some multiutility module with mixer and mult.
Behringer has Four LFO (clone of Xaoc Batumi) and Steps (clone of Mutable Instruments Stages). You can also load Qiemem's custom firmware to it which will allow you to control LFO polarity and frequency range though I don't recommend it if you're complete beginner. https://github.com/qiemem/eurorack/tree/v1.0.0/stages
There are clones of Mutable Instruments Links and Kinks which are great multi-utility modules. If you're in UK BeepBoopElectronics has lot of various utility modules. https://beepboopelectronics.co.uk/
https://beepboopelectronics.co.uk/product/passive-attenuator/
https://beepboopelectronics.co.uk/product/bonds-and-structures-links-clone-eurorack-buffered-mult-mixer/
https://beepboopelectronics.co.uk/product/2hppassivemult/
https://beepboopelectronics.co.uk/product/cuts-and-folds-kinks-clone-eurorack-utility-module/
I'm also not sure if you have some kind of mixer or audio interface but if not you'll need some output module to plug your headphones in. BeepBoopElectronics also has simple 2hp headphone output module.