Rome in early (?) April, for somebody coming from a hoot country is not sandal weather! Unless you are from northern europe and wear it with socks, but that is not hot countries by any account and not a look I would recommend.. 8 to 18 degrees is sort of a guideline IMO, it can go from say 3 or 4 degrees to 25 - I would check long term weather forecasts just before packing, because it´s totally different if you need to handle days of 8-11 degrees with rain or lots of sunshine with days of 18-21. By the way if you are coming from a hot place, 18 or even 21 is not HOT weather.

Things I would recommend in general:

• one windbreaker or trench, with pockets and hood. If it´s got a removable warm lining, you are all set (zara basic currently has a navy one which is great). If not check for something warm (jacket, sweater, denim jacket) you can wear underneath the windbreaker.

• two pairs of trousers, one jeans.

• one pair of leggings or tights (that you can layer under trousers if very cold). Leggings might double with sleepwear.

• longish long sleeved tunic or dress, that you can wear on its own or over the leggings /tights

• one sweater or cardigan. Maybe two, depending.

• one shirt

• plenty of layerable light tops

• two scarves both light, maybe one wool, one silk for extra coziness in case of wind or rain

• two pair of shoes, the hiking ready boots and something you can slip on or off easily enough. They both must be very very confortable and have decently thick soles.

• one pair of flip flops for the shower (if you are staying in cheap places or student like places)

• as many underwear and socks as you think you need plus two more pairs of each

• something to sleep in.

• large tote or backpack for day time touristy thing, plus small (not too small!) bag you can wear cross body to keep wallet and electronics.

• one small, as small as you can find, umbrella.

• sunglasses

• non valuable, small jewelry, etc.

pick a base color (italy in springtime, anything but black would be my recomendation) and go with solid simple things except maybe go wilder with some of the tops and the scarves.

have fun.