FF and croped sensor is not 'better' or 'worse'. I think most ppl would like to think FF is 'better' because for the same resolution (mpx) , the FF sensor is able to give a better SNR in that each 'pixel' is of a larger size.
If you ever shot film , that is FF. Really no big deal. Just use the lens as it is...no conversion.
There is a slight diff in the depth of field . A croped sensor will give you slightly deeper DOF. Example, if shooting at 100mm, a FF gives you very shallow DOF. Whereas to have 100MM equivalent, a crop sensor camera "only require" ~ 70mm....something like that lar.
If you predominantly shoot with lens of less than 50mm, then perhaps you will enjoy a FF cam. However, with all the digital lens coming out theses days, you really have lots of choices in terms of wide angled lenses.
btw, if you are very image quality conscious, you would NOT want any lens other than the BEST in it's range to put on the FF body. Even then, there is still 'flaws' especially at the edges if you look close enough. Personally, I really dun see the point of being so 'fussy', but of course, there are many out there who would beg to differ
Enjoy shooting, FF and cropped sensor really is not that of a big deal for most folks. Some ppl after switching to FF, realized they still end up with the same shots....becasue their style is fixed
Lens? Any EF lenses except EF-S. Some 3rd party lenses are also not compatible. FF usually is better for dynamic range and noise control. It also has advantage on making full use of ultra-wide lenses without having to buy EF-S lenses.