Hi! It really depends on what you plan to do and how do you want to travel. If you want to wander around a lot, staying in rural areas away from towns or cities and stuff you need to bring a lot of stuff. If you want to go from town to town, you can go lightweight.
For example, I was in England for (in total) three month, traveling by coach/bus and staying in hostels mostly, but also slept outside. I needed: Toiletries, a few clothes to have something to change into when you want to wash your stuff, underwear, socks (!!!), sleeping pad (could be substituted by cardboard) and sleeping bag.
Everything else I hauled (esp during my first trip) I rarely or never used. Never used my tarp. Or my paracord. Used my rain poncho once in Bristol (but only to try it out). Same with my multi tool. In fact I gave it away to a friend in Brighton, so she could tune her banjo.
Don't pack too much. If you stay near civilization, you can always get something for cheap if you feel the need. For example, in January in Bristol I got cold hands and I forgot to pack gloves. So I got a pair of woolen gloves at Poundland for one pound. Found it annoying to carry essentials (like cans of ciders
) in a plastic bag all day long having my large backpack in the hostel. So I bought a simple, cheap backpack at Primark for 8 pounds as a daypack. (I still have it, it's the one shown in my current avatar picture). Bought lots of cheap socks, too.
As said, it depends on the (potential) situations. If it could be that you end up stuck somewhere outside cities and have to camp in the woods, bringing a tarp might be a good idea. But don't pack too much. Don't be like "this could be useful ... and ... well that could be useful, too ... and yeah this also". You will end up needing a mule to carry all your luggage.