Hi Kristina -
As ever, can’t fault Stuart’s (isn31c) advice. I can add a little about favourite hikes in the area(s), some strenuous, some less so.
From the Lodore Swiss Hotel (bus from Keswick) climb to Lodore Falls (best viewed immediately after rain) and on reaching the head of the falls head left then right to pick up the ‘Caffel Side’ path to the isolated village/hamlet of Watendlath. Climb right uphill to ultimately descend back into Borrowdale and the village of Rosthwaite where either follow Cumbria Way back or catch the bus in Rosthwaite, both times to return to Keswick.
From Coniston, take the Walna Scar road to EITHER climb to the summit of Brown Pike, follow ridge over Dow Crag summit descending to Goats Hause and climb The Old Man of Coniston, descending via Low Water into Coppermines valley and back to Coniston OR from the Walna Scar road take The Cove path to Goats Water passing along its shore with Dow Crag towering on the far side to climb Goats Hause to reach the Old Man, descend as above or a right turn below Low Water takes you back out to the Walna Scar Road. Alternatively, climb the Old Man via Low Water and follow the ridge round via Swirl How to descend the Prison Band to Levers Water where a right turn along its far shore returns you to Coppermines Valley and thus Coniston.
From Grasmere ascend Helm Crag and ascend up the ridge over Gibson Knott (C2C high level route) to the head of Easdale and return via the C2C lower route back to Grasmere.
Helvellyn is usually climbed from Patterdale/Glenridding via the ‘Hole in the Wall’ (no hole anymore, just two ladder stiles) and across Striding Edge (needs care and will be hellishly busy on a fine day), returning from summit via Swirral Edge and Red Tarn to retrace your outward steps. However the last time I climbed Helvellyn we parked at Dunmail Raise and climbed Raise Beck to cut above Grisedale Tarn and climb to Helvellyn via Dollywaggon Pike and Nethermost Pike, returning on the Wythburn path from the summit almost to the valley bottom, to follow a track, then path back to Dunmail Raise.
Skiddaw, climbed from Keswick via Latrigg and Skiddaw Little Man is a steady if relentless climb and an out and back route, so I much prefer the alternative of taking the bus to Red Mire House (I think I need to double check that) and ascending via Ullock Pike and Carlside to Skiddaw summit and returning to Keswick via Latrigg etc.
Finally an ascent of Catbells is fun, which is why it’s de rigeur in Rick Steves posts! Take the launch (anti clockwise round Derwentwater unless you especially want to see it all) from Keswick to Hawes End and climb the obvious tracks left up Catbells to its summit. You can go further from here over Maiden Moor, High Spy and Dalehead to complete the full circuit of the Newlands Valley, but these days I’m happy enough to climb back down Catbells and follow the footpath to Nichol End Marina and thus to Portinscale and back to Keswick.
Needless to say you need the correct attire and footwear for all these walks and an OS map and compass with a good idea of how to read/use them as well as a guide book. Alfred Wainwright’s ‘Pictorial Guides’ remain the touchstone for most hill walkers, but others are available.
Hope this gives you some food for thought, although I’ve barely sctrached the surface here!
Ian