It's a standard deck that i'm gonna start using at my local mtg store but wanted some advice on it before i brought it, since its the first deck i've built. https://deckbox.org/sets/1625513 I don't want to spend much more but if a few decent cards would improve it massively i'd be willing to pay around £25 more.

I would like to know what the main theme of the deck is. I see some energy elements and some +1 counter elements, but it doesn't appear there is enough of either to really work consistently.

Also you are going to need more lands to support your high casting cost spells. I would start with 24 and adjust from there.

I would suggest searching some decks that use cards you already have and see what they are doing. Here are a couple examples.

https://deckbox.org/sets/1622837

https://deckbox.org/sets/1612475

Good luck and have fun.