Has anyone got any tips of things I can do with my 4yr old and 1yr old?

Following for suggestions as I am literally in the same boat. Finding it very tricky atm!

Bath city farm is great and free x

Soft plays, aquarium, farm yard, zoo, toddler villages (if any near you), playgrounds, trampoline toddler bounce sessions, we have a “tiny gym” session near us too they both love, have a look at “ Danny Go” on YouTube for exercise silly fun. I have a 4.5yo and 22m old and the above keeps them both entertained

How old is your 1yr old? Meaning, are they just one or are they 18m+?
We go to the park a lot, the farm. Soft play, playdates with friends, play group, forest school and just get in the garden.
They both love a marble run (but not if your little one is the kind to put things in their mouths) sensory trays, painting. My son (4.5) likes to paint those plaster of Paris figures, my daughter (22 months) mostly just dips the brush in the paint then in the water 😂 she also loves colouring while I do some maths and phonics games with the older one. We also bake together (just don't worry about the mess or the actual final product... Normally I give the toddler a spoon of the cake batter while my older one helps with putting it in the cases to bake!)
But, given all that.... We do still watch a lot of TV, have arguments, fighting over toys, me absolutely losing my mind..... It's HARD.

It's tricky adjusting to life with two and I think the adjustment takes longer than people realise. Just as you get used to having a baby again you're older childs needs start to change.
Today we're at a free family fun day. With the weather being nicer we're getting outside a lot more and I find that eases things all round! Easier to keep them entertained, the house is less of a mess because we're there less, they're behaviour is easier because they've been able to be active. Honestly though we just take it one day at a time!

I just got a mud kitchen for the garden and both my 4 and 1 year olds are loving it. Water, mud and some secondhand pots and pads .. stuff to stir around. Stick some washable paint in the water and it makes it colourful which they love. They put flowers and grass in it and 4 year old does imaginary play (I’m making a cake mummy etc) and 1 year old stirs the water and just enjoys the splashing