The first problem is no dentistry lasts forever . In order for you to get the best results you need to have a dentist you trust who can help you address the diet and lifestyle issues that caused the missing/broken teeth and to help you maintain your teeth and keep the best results for many years for your investment.
Every time you put a drill to a tooth you shorten its lifespan . Veneers and crowns need replacing every 10 years or so and each time more tooth is taken away. Implants need maintaining and parts need replacing , they are also more likely to be lost through gum disease than your own teeth.
The very best dental treatment is that which keeps your own teeth , untouched if at all possible . That's why whitening and braces is so good because it makes teeth look better , easier to clean with no damage .
Your first port of call should be a good general dentist to get your teeth and gums in peak condition . Tell them what bothers you and what you want to achieve. They can then discuss with you what may be possible, the limitations and lifespan of treatment and refer you on to a trusted colleague such as an implantologist or cosmetic specialist if this is appropriate.
Whatever treatment you have should be close to home ish as even the best treatment, in the best hands can go wrong and need correcting.
This is going to be a long term project as if you need extensive treatment it is best done in stages and in time to allow you to be able to maintain a healthy mouth afterwards.
Certain treatments eg implants are not suitable if you smoke, or have diabetes , or dry mouth or are on certain drugs or have uncontrolled gum disease. Braces are not suitable if you have uncontrolled gum disease or decay .
Finally some tooth damage is caused by grinding and clenching and this can also affect the life span of eg crowns, veneers and implants which will fail quicker than your own teeth , so if you are a grinder or clenched this will have to be addressed first .
In synopsis find a general dentist who is recommended by friends , family etc , get the basics done and ask their advice about the issues you want sorting.
Invest time in changing cleaning, diet etc both for the health of your teeth now and in the future.
Don't expect a quick fix , it's taken many years for your teeth to become unsatisfactory , to get a stable result that will last you many years it will take time and , sorry to say, money.