An altar is the focal point of worship and magick. Everything used for magick is placed upon it. The Lord's stuff goes to the right, the Lady's stuff goes to the left like at dinner. Unless you worship just one, then the deity is placed at the top as the focal point. The altar faces North traditionally, but you may face it West for the Goddess or East or South for the God depending upon their association. It is nice to have a prayer room or big closet, use your foot locker to use as an altar toeep your stuff locked in. It is fine draw the circle upon the floor such as the pentacle or a foot mat, a big paper drawn with the circle, and the walls can be scribed with symbols (even glow in the dark ones). The pentacle is placed in the center. The offering plate goes upon it, and anything you want to offer is placed upon the plate, but you can also place your cauldron there.
The athame goes South just as Fire can go South. West is the chalice of wine, apple juice, libation of honey, milk, and wine or juice. Leave the offerings there all day. Replace daily. The incense goes East as does the wand for Air, but do as thou will. Your desire is your invitation. Other tools can be kept under or on the altar. Use it for spell work and prayer and worship. Stones, herbs, scissors, thread. mirror for scrying, pentacle, etc., but its your choice. In nature use a stone as an altar, everything carried in your tool carrying bag (book bag is fine or traditionally red flannel bag). You may find a place with all your necessities. Tree North, river East, graveyard, etc. Nght is traditional to keep hidden.
I hope this helped you. Blessed Be )O(