Painting Help

[ishy]

I’ve now finished caulking up all the holes, which there were too many.
I’m now gonna paint this as an accent colour to match my draw as grey but how do I paint it?
What type of paint do I use to paint this. At the moment I have some spare woodworks paint.
Also do I need to sandpaper it to make it smooth or shall I leave it how it is?
Sorry if I may sound dumb as I’m new to this all and I’m 16.
Pictures:
1:

2:

3:

Also the wall on picture 3 will be painted grey
If theres anything else I maybe doing wrong please inform me
Also the caulking job may look a bit messy as some of the holes were very large and I couldn’t really glue it together ish
Thanks everyone for the help!

 

[ishy]

Sorry for the late reply I received the emails on junk.
Basically when I was filling some of the cracks and gaps I think the insulation foam (yellow dried spongy) I don’t really know what it is was sticking out. And when I tried to fill the gap the foam then was pushed back I think the gap went up-to the actual roof I think so the hole was a bit too large to join.
So I just joined the foam together on the ceiling and just caulked on top of the foam.

Here’s one picture:

Wasn’t sure at all what to do so I just caulked into it a bit and filled it until it came a bit out

Also this support beam( I think) was cracked and soft so I scraped it and all this came off




I have no idea what it is but I think it was soft because there was a leak there from last month which was just repaired.
I scraped it off as it was brownish and soft and some dust pieces came off and some hard pieces like some kind of flour concrete came off
Then I just caulked on top of it a bit just to conceal everything off.

And for the paint I think I might just paint over it and leave it how it is I don’t see a point in sand papering it or anything

 

[ishy]

Also here’s the part where the hole was too large so I couldn’t properly filll it in

 

[ishy]

Yeah the actual slate on the roof was damaged and there was also a hole there so they patched it up and replaced the skates. The water was seeping through on heavy rain however normal rain didn’t really do much
The water going through I’m guessing started rotting or did something on that wall . I don’t really 100% know what happened but all I know is that the roofers patched a hole up and did something else as my dad did that stuff

 

[ishy]

Btw thank you all for the advice