Which organisation/think tank/group should I join if i have those beliefs?

[BeGreenBear]

I’m at the point where I want to get more involved politically, but I don’t know where I fit.
I don’t like how much money is poured into benefits and refugees, especially when we’ve got so many problems here already. I’m also not a fan of the monarchy — it feels outdated and expensive.
What I do want is more investment in proper public infrastructure: better transport, properly funded schools, functioning NHS, and well‑maintained local services.
I’ve looked around but every party seems to either focus on handouts and identity politics, or else they cling to the monarchy, which I don’t support.

Tbh it sounds as if you'd be most at home with Starmer's Labour - refusing to lift the two child benefit cap, PIP cuts for the disabled, increased investment in public services, an obsession with 'taking back control of our borders' and rhetoric about the UK becoming 'an island of strangers'. I doubt you'll find a party that doesn't support the monarchy, benefits and immigration simultaneously.

As pp says, you will struggle to find one which fits all criteria. Perhaps think about what your priority is - if it’s capping benefits and sending boats back - Reform is the party for you, but you’ll get nowhere with the idea of a republic.

Alternatively, if getting rid of the monarchy is important, take a look at Jeremy Corbyn’s party.

A good way may be to ease yourself in by taking an interest in your local community council/ or local authority and push for change locally.

I've had ideas like this from time to time. It never really mattered what the issues that I was concerned about were and they differed depending on which stage of my life I was in but the experience always turned out to be the same:

The cause might have been awfully just but the people were just awful. You will be chased constantly for donations, memberships, subscriptions, help with fundraising and so on and so forth because at a lower level, that's all you will be good for. Cash.

In return you will get access to monumentally boring meetings wherein the most extreme members will take over and spout nonsense, get invited to terrible social events in strange locations and then finally give up because nothing of substance ever gets done.

If you are really unpeturbed by my warning, pick something very small, very local and in which your personal experience or expertise will count.

In your shoes I’d educate myself about the facts re refugees & benefits before I plunged myself into politics!
Where are you currently getting your ‘facts & figures’ from? Genuine question op!