Knocking, clacking when braking or rolling out, but not always

Hi, I did it again. A few days ago Ford Escort (tournament, 1.4L/75hp, petrol engine, Bj.98 (ABS) – about 90,000 ran) bought and zero idea of car technology. Logically, I did test drive. Except for noise from defective wheel bearing on the rear right everything easy. Seller (screw) changed wheel bearing before handover. Cross handlebars should also have been renewed (because of TÜV July 2007). Battery was flat, got now the one of my old Opel inside. It took a bit of time, because I didn’t get rid of the screws from the mount. After that, he started looking around (seemingly seems to be normal), but now he’s running OK again, except that he doesn’t always start the first attempt at the start. And now to the real problem: when I walk off the gas (light or something) suddenly a strange knocking or clacking is to be heard. When I brake it gets louder. Strangely enough, it’s not always like that. Today I am about 20km away. on the way back (bad roadway, but same distance as on the way) it suddenly started again after a slightly stronger unevenness. The sound seems to come from the front. I can exclude lots of flying parts in the car. Do not need repair instructions, because I can not do much for myself anyway because of lack of suitable space, tools and idea. But a few good tips, which could be the reason for this would be really great. h in a workshop don’t like to let it go over the ledges. They may start a whole new thing for me. So always with the good advice and already thank you in advance.