first hand:

raise more preflop!. I would make it atleast 0,60 , probably 0,70. I prefer playing these hands against 1 opponent and not 2. if you are against 1 opponent you can make this continuation bet of about 3/4 the pot. If you get called, check the turn and fold to heat. If you get raised on the flop, fold versus any decent player. Of course if you have reads on villain being a total maniac other rules apply .

The river bet is probably the worst part, since he is not laying down an ace with that river . check /fold the river.

second hand again, bet alot more preflop. ISOLATE. i probably make it 1,00 here. Then make a c-bet of a decent size and hope he doesn't play back. Betting this hand on the flop with 3 other players is suicide. one of them has atleast a king, and probably more.

good luck!