Can I keep all my crystals together

Yes. Obviously they are your crystals and you can arrange them whichever way you want, I say trust your intuition. Some crystals have energy that enhance or conflict each others flow but as the intention setter your feelings around your crystal especially if you are using them as a healing tool is all that matters.  

How do I clean my crystals

Cleaning your crystals can help eliminate build up of negative energy and dirt. But not all crystals can be cleared in the same way. Quartz Amethyst Citrine etc, can be washed in water. If in doubt check the mohs crystals hardness scales and you can't go wrong. The only exception to the rule is the tangerine quartz high level ranking hardness but its not water worthy due to iron levels. Also crystal with ite cannot be submerged in water for example selenite flurnite azurite calcite again always check mohs.

How do I recharge my crystals

Sometimes different crystals like to be charged in different ways some crystals belong to sun some belong to earth others belong to the moon etc the more you fall in love with them the more you understand their needs.  For instance moonstone likes to be charged under a full moon or washed or recharged in moonwater. Citrine absorbs the sunlight so well and enjoys time soaking up the energy boost it gets to give it its golden luminosity. The sun helps power it up with prosperity, and confidence.

Here are all the ways you can charge your crystals .....Sunlight Full Moon Moonlight Smudging Intention Sounding Meditation Singing Bowls Tunning Forks Bigger Crystals with smaller crystals 

How do I choose the right crystal for myself

Trust your intuition set your intention don't overthink and I truly believe crystals choose you. 

How long will it take for the crystal to work

The more time you spend learning about your crystal and believing in it and by setting your intentions to the crystals energy field to achieve your goal. These things can take time to settle adjust and develop. Depending on individual requirements and work needed and care taken of crystal. Just remember energy goes where attention flows. 

Do crystals shapes have different uses

Yes, there are many different kind here are a few spheres, clusters, tower, egg, wand, geode, twin crystals, pyramid and cube.