As above, this year was bad for everyone so take heart! Start EASY. Toms, peppers and chilies = good, but the latter take a while to get going so remember to start them early on an indoor windowsill. I also find I start my tomatoes earlier and earlier each year - and fewer! A few good healthy plants get planted into the soil in the greenhouse, then as I pinch out I pot up the pinchings and get next crop from those - some in greenhouse, those there isn't room for outdoors.
I've never yet managed a full-size ripe pepper (but we eat them anyway, tho' small)
Cucumbers are a bit harder I think; several things to go wrong. Also don't bother with aubergines (if you were thinking of it!) - you cannot grow them cheaper or better than you can buy them in Lidl.
But DO also use your greenhouse (no. 2) for starting off Courgettes, Peas, and Beans (though this ultra-wet year I finally got a crop of peas by starting them off on the kitchen windowsill where no slugs or snails could get at them). Also put troughs and pots inside and succession sow with spinach, rocket and radish; and, come early spring, lettuce, spring onions, a few carrots, and above all, cut and come again salad stuff