For Sunday, go around 1pm to “le marché des enfants rouges” which is some kind of trendy market where cool people hang out and get brunch: www.les-enfants-rouges.com , and also described on spotted by locals
From there you can take a walk into “le marais” and explore the area, like rue des rosier, rue vieille du temple. Le Marais is the gay area Paris. You’ll find some great vintage shops and designer clothes in the same street, together with more mainstream fashion. Good café and restaurant in the surroundings. In any case, the paved streets are worth the walk.
Then you can head towards République (consider taking the metro) and from République get to the Canal St Martin, where you’ll find some one of my best pick for late afternoon drinks: Le Comptoir General. Few other good options in the area, including cocktails at “Le Coq” and café/wine in “Chez Prune”.