how to correct html errors

I’ve been advised that following a check of my WordPress site using a ‘mark-up validator’ I have the followng errors in the html that I need to correct. Problem is I don’t know where to find the errors in order to correct them! Can anyone help? Here’s the report:

Validation Output: 3 Errors
1. Line 11, Column 158: character “&” is the first character of a delimiter but occurred as data
2.
…ing Well. Ideas for Better Living. Time-saving & Money-Saving tips & ideas.” />
?
This message may appear in several cases:
? You tried to include the “<” character in your page: you should escape it as “<“
? You used an unescaped ampersand “&”: this may be valid in some contexts, but it is recommended to use “&”, which is always safe.
? Another possibility is that you forgot to close quotes in a previous tag.
3. Line 11, Column 178: character “&” is the first character of a delimiter but occurred as data
4.
…ing Well. Ideas for Better Living. Time-saving & Money-Saving tips & ideas.” />
?
This message may appear in several cases:
? You tried to include the “<” character in your page: you should escape it as “<“
? You used an unescaped ampersand “&”: this may be valid in some contexts, but it is recommended to use “&”, which is always safe.
? Another possibility is that you forgot to close quotes in a previous tag.
5. Line 124, Column 233: there is no attribute “addthis:url”
6.
…x addthis_default_style ” addthis:url=’https://getsmart-livewell.com/blog/&#8217; add…
?
You have used the attribute named above in your document, but the document type you are using does not support that attribute for this element. This error is often caused by incorrect use of the “Strict” document type with a document that uses frames (e.g. you must use the “Transitional” document type to get the “target” attribute), or by using vendor proprietary extensions such as “marginheight” (this is usually fixed by using CSS to achieve the desired effect instead).
This error may also result if the element itself is not supported in the document type you are using, as an undefined element will have no supported attributes; in this case, see the element-undefined error message for further information.
How to fix: check the spelling and case of the element and attribute, (Remember XHTML is all lower-case) and/or check that they are both allowed in the chosen document type, and/or use CSS instead of this attribute. If you received this error when using the <embed> element to incorporate flash media in a Web page, see the FAQ item on valid flash.
7. Line 124, Column 284: there is no attribute “addthis:title”
8.
…art-livewell.com/blog/’ addthis:title=’Welcome’ ><a class=”addthis_button_fac…
?
You have used the attribute named above in your document, but the document type you are using does not support that attribute for this element. This error is often caused by incorrect use of the “Strict” document type with a document that uses frames (e.g. you must use the “Transitional” document type to get the “target” attribute), or by using vendor proprietary extensions such as “marginheight” (this is usually fixed by using CSS to achieve the desired effect instead).
This error may also result if the element itself is not supported in the document type you are using, as an undefined element will have no supported attributes; in this case, see the element-undefined error message for further information.
How to fix: check the spelling and case of the element and attribute, (Remember XHTML is all lower-case) and/or check that they are both allowed in the chosen document type, and/or use CSS instead of this attribute. If you received this error when using the <embed> element to incorporate flash media in a Web page, see the FAQ item on valid flash.
9. Line 124, Column 351: there is no attribute “fb:like:layout”
10.
…_button_facebook_like” fb:like:layout=”button_count”><a class=”addthis_but…
?
You have used the attribute named above in your document, but the document type you are using does not support that attribute for this element. This error is often caused by incorrect use of the “Strict” document type with a document that uses frames (e.g. you must use the “Transitional” document type to get the “target” attribute), or by using vendor proprietary extensions such as “marginheight” (this is usually fixed by using CSS to achieve the desired effect instead).
This error may also result if the element itself is not supported in the document type you are using, as an undefined element will have no supported attributes; in this case, see the element-undefined error message for further information.
How to fix: check the spelling and case of the element and attribute, (Remember XHTML is all lower-case) and/or check that they are both allowed in the chosen document type, and/or use CSS instead of this attribute. If you received this error when using the <embed> element to incorporate flash media in a Web page, see the FAQ item on valid flash.
11. Line 160, Column 375: character “&” is the first character of a delimiter but occurred as data
12.
…com/blog/terms-and-conditions/”>Terms & Conditions | <a href=”https://getsm…
?
This message may appear in several cases:
? You tried to include the “<” character in your page: you should escape it as “<“
? You used an unescaped ampersand “&”: this may be valid in some contexts, but it is recommended to use “&”, which is always safe.
? Another possibility is that you forgot to close quotes in a previous tag.