Your dentist should discuss treatment options with you and help prioritize treatment. It may take a couple of visits to reach decisions regarding your treatment plan. This may require removal of decay, root canal therapy, or extractions. The second priority should be to treat any remaining cavities and periodontal disease. Some of the teeth may require crowns in the future, depending upon the extent of the decay, but you should at least have the decay removed and a filling placed to prevent further tooth destruction.
Periodontal health is also important.
If the supporting bone and gum tissue are not healthy, restoration of the tooth may not be prudent. Crowns and other restorations to replace missing teeth can then be done later. If necessary, temporary restorations may be placed in the meantime. You should be aware that as a former drug addict, your tolerance to local anesthetic and pain medications will probably be changed. Drug addiction can cause liver dysfunction.