i have a painless pea sized lump just under the skin near my abs what could it be

This could be cyst, a lipoma or benign lesion. It could represent another type of growth and from the DES ription alone it is impossible to give a definitive answer. It is best ot see a doctor for proper diansosis and possible removal .

Generally, the mini tummy tuck is an  operation that  produces very limited results and is very rarely indicated. It involves a shorter incision but does not address the majority of the abdominal wall issues present for most patients who present consultation, after pregnancy and/or weight gain/loss. Seek consultation with well experienced board-certified plastic surgeons for more precise advice

Crunches are good for this. There are variations on this, and some health clubs & gyms have equipment (machines) that can help with this goal. Consider seeing a physical therapist or a trainer, especially if you are not used to this type of exercise.

Six-pack or eight-pack "abs" are particularly difficult to get, because you don't get them just from exercise. It also takes very low body fat levels, well under 10%. So you have to lift like crazy, probably 5-6 days a week, and observe a very strict diet, as well. I would advise finding a trainer and maybe even a nutritionist. You should be able to find instruction for training online.

You can exercise your abdominals every week. A day or two of rest every 5-6 days or so is a good general recommendation

A strong abdominal program and core exercises will build lower abdominal strength and "muscles." I would suggest working with a personal trainer but specifically those exercises that bring the legs up while keeping the pelvis stable will work on the lower abs (ie seated leg raises or alternating leg raises.).

Strength training is the best way especially when it is associated with a low carbohydrate diet.

Perfect symetry is the execption rather than the rule. Some degree of assymetry is to be expected.

Must reduce body fat composition first. Concentrate on diet and cardio. If you trim down enough, your natural abds will start to show. You can then build them with crunches, push-ups, etc.

often sit ups