Freeview only TV - how do I get amazon prime & catchup on it

Hello - I'm very confused by all the set top / kindle stick options out there, and I'm really hoping someone can help me out?

I'm separating from partner and my toddler loves to watch programmes available on amazon prime on the smart TV.

when I move out though I'll only have a 'non smart' LG TV with inbuilt freeview.

My question is, what are my options please for turning the LG into a TV where amazon prime will work, and also catchup on bbc, itv, C4?? if this is even possible? Or do I need to buy a new smart TV??

Thank you so much for any help!