This Friday 20th March, there will be a Total Solar eclipses that we will be visible across Northern Africa, Europe and Russia. How much of the sun will be eclipsed is dependant on where in that area you will be. If you are situated in the Faroe Islands then the Sun will be totally eclipsed by the Moon. The GIF at N.A.S.A.'s will show where's affected by the Solar Eclipse and by what degree.
In London, providing the weather is good, it is expected to be about 80-90% eclipsed. Even though it is only 80-90%, it will provide a spectacle to see. Unlike at 100%, the sky will not go dark. People in Paris, Berlin and Madrid should all being about so see part of the Eclipse. Looking at the Sun even for a short time and even when eclipsed can cause blindness. It is recommended that you buy special glasses to see the eclipse to protect your eyes. The "Sky at Night" magazine are giving away a free pair of solar glasses, if the magazine doesn't have them, ask for them when you buy.
If on the other hand, you need more, you can buy them at reputable outlets. The ones I've bought to watch with come from Eclipse Glasses and they come in packs of 5+. The only negative thing I can say about them is that they got sent via 2nd class post. They've been inundated by requests so get in quick although it may be too late now. I've not been paid for mentioning them and have no connections to them, there are other providers out there. 3d Images look like a trading name of Eclipse Glasses. First Light Optics would seem to have sold out.
If you have a telescope or binoculars, do not look at the Sun, it will burn your retinas. If you have special filters then they can be used but not with ordinary filters, you'd need to ask a professional and not chance the gear you have. If you miss the Eclipse, the next one will occur in the UK on 12th August 2026. 1. It will sadly be a partial eclipse again in the UK but people in Northern Spain will get to see Totality.