is this a good graphic card for me?

Honestly I think the gtx 950 is £15-20 overpriced at the minute.
A month ago they were going for £105

Consider the rx 460 because

1. Its cheaper
2. It performs pretty much the sane as the 950 on dx11 titles
3. It performs better than the 950 in DX 12 titles

XFX RX-460P2SFG5 PCI Express Graphics Card - Black https://www.amazon.co.uk/dp/B01JGQU8WI/ref=cm_sw_r_em_apa_C4DRxbWFC61SN

^ that card is completely bus powered (doesn't require a PSU power connector)