Looking into my first Ethereum Investment!

I know people are gonna say wait for the dip but at the moment I'm hoping for it in the long run, not quick gains so I don't care too much. I've downloaded trust wallet and it says to buy from MoonPay. Is this the best way to buy ethereum? just thinking of doing a small £125 for time being and slowly building up over a few months as I don't have a huge amount of money I can afford to lose at the moment!