I'd say get an Asus Prime B350M-E motherboard:
https://www.newegg.com/global/uk/Product/Product.aspx?Item=N82E16813119020&cm_re=ASUS_b350-_-13-119-020-_-Product
For the RAM: https://www.newegg.com/global/uk/Product/Product.aspx?Item=N82E16820232609
And then for the CPU, get a Ryzen 5 1400...